Year
| Case Name | Opening Date | Last Update | Status | Description |
|---|---|---|---|---|
| PM_MOD_23027 | 2023-01-27 | 2023-01-27 | Note | Decommissioning of the MODIS C6 Forward Processing C6 Forward processing of Terra and Aqua MODIS Land data products will be discontinued, on February 15, 2023 (02/15/2023). The C6 land data products have always suffered from known calibration issues that were discovered by the instrument Cal/Val team after the completion of the C6 reprocessing. The main issue among these being the increased impact of optical crosstalk in the Terra PV LWIR bands 27-30, that had made retrieval of most atmospheric parameters infeasible, indirectly impacting some of the land products that were dependent on these atmospheric retrievals. The Collection 6.1 (C61) corrects for this and some other critical calibration issues and also has a number of product specific improvements and enhancements that are listed in the C61 change document<A href="https://landweb.modaps.eosdis.nasa.gov/data/userguide/MODIS_Land_C61_Changes.pdf"> here.</A><br><br>Given the improved performance and calibration of C61, users are requested to switch to C61 for all of their MODIS land data needs. DAACs, will retain the C6 historical land data products for a further period of 6 months, following this decommissioning of the C6 forward processing, and will decommission all C6 land data products after the expiry of this 6-month retention period.<br><br> |
| PM_MOD_22335 | 2022-12-08 | 2022-12-16 | Closed | Unavailability of MODIS Terra data 2022.335 (12.01.22) MODIS Terra production has been put on hold starting on day 2022.335, 03:15 UTC onwards. The production has been failing in the L1 geolocation process and may be due to the orbital drift of Terra, following the CEMs. The geolocation team is investigating the issue and further updates will be posted as and when ready. The image below shows the global browse image for the Terra Surface reflectance (MOD09) on December 1st, 2022 (2022.335), where the data production failures have impacted this day in the forward processing.<br><br><br> |
| AS_MOD_21280 | 2021-10-07 | 2021-10-12 | Note | Terra Data Loss 2021.280 (10.07.21) On October 7th, 2021 (2021.280) an approximately 5 minute data gap occurred on Terra MODIS due to a contact error from 10:28:50z to 10:33:38z. Attempts to recover this data loss were unsuccessful. Processing has been closed and the data is not recoverable. Below is an example image from granule 10:30, which shows part of the data gap during a daytime orbit over the Arctic Ocean in the L1B geolocation and radiance layers. |
| PM_MOD_00083 | 2015-05-22 | 2015-05-22 | Note | A Terra MODIS thermal band calibration activity 2000.083 On 03/23/00, Terra MODIS data quality was negatively impacted by the thermal band calibration activity (MODIS Events BB Warmup/ Cooldown). The calibration activity occurred over portions of Asia. This impacts the L1B Thermal bands and all downstream products. Below is an example of the global browse image of the downstream MOD10 snow product where the data impact is observed as No Decision class over Asia. For detailed information on the calibration activity users can reference MCTS <A HREF="http://mcst.gsfc.nasa.gov/modis-events-categories/routine-calibrations/bb-warmupcooldown?event_date[value][year]=2000&modis_mission=All&page=3"> records of MODIS Events BB Warmup/ Cooldown. </A> |
| PM_MOD09_15076 | 2015-03-17 | 2018-09-26 | Note | Dead detector fill values bands 5,6,7 Due to a previously identified dead detector, striping occurs in the L1B reflectance granules for bands 5, <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=75">BAND 6</A> and <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=76">BAND 7</A> of Terra MODIS. The downstream L2 MOD09 product handles the dead detector fill values differently across surface reflectance bands 5, 6, and 7. The MOD09 surface reflectance replaces the dead detector in band 5 with interpolated values from neighboring detectors. Dead detectors in bands 6 and 7 are replaced with values generated by a destriper, a preprocessing step run within the surface reflectance process. However individual band quality bits in the "500m surface reflectance band quality" SDS is set to indicate the dead detector states for all the bands (5, 6, and 7). Hence users are advised to check the band quality flag for dead detectors even though reflectance values may be in the valid range. <br><br>The following example shows the image of reflectance band 7 and 6 in the L1B and MOD09 swath product. The last image shows the quality flag QC_500m_1 from the L3 MOD09GA, which identifies striping from dead detector values that are also observed in the L1B data. Further review of the individual quality flag bits for each band identify the dead detector state for these observations. |
| PM_MOD_14160 | 2014-06-09 | 2014-06-09 | Pending | Incorrect production date time in LOCALGRANULEID and PRODUCTIONDATETIME metadata The metadata 'PRODUCTIONDATETIME' and the production date time field in the metadata 'LOCALGRANULEID' of MODIS L1B, Atmosphere and Land data products may be incorrect in some of the data granules where PRODUCTIONDATETIME seems to be behind the DATA ACQUISITION TIME by several hours. The problem has been traced to incorrect unix system clocks in some of the minions used in the data processing at MODAPS. The metadata PRODUCTIONDATETIME stores the time when the granules were made at MODAPS and will not otherwise decide quality of the product or the sequence in which the products are generated and processed at MODAPS, and hence will not have any impact on data quality. At this time there is no plan to fix these metadata error.<br><br>Example: Metadata LOCALGRANULEID from file MOD021KM.A2014060.1555.005.2014060071056.hdf seems to indicate that granule acquired at 15:55 GMT on March 01 of 2014 has been processed earlier to the data acquisition, i.e. processed at time 07:56:00 on the same day.<br><br>LOCALGRANULEID: MOD021KM.A2014060.1555.005.2014060071056.hdf <br>PRODUCTIONDATETIME: 2014-03-01T07:56.00<br><br><br><br> |
| CC_MOD07_13340 | 2013-12-06 | 2013-12-06 | Pending | Top levels of some profile data are all fill Some of the C6 MOD07 moisture profile data are all fill for the top layers. This is not the case for the equivalent C5. The first four images below show the four top layers (05, 10, 20, and 30 hPa) of the dew point profile from MOD07 for granule 2003002 14:05. All pixels are black, indicating fill values. The second set of four images shows the equivalent set of dew point profile layers for the same granule from C5. Valid data are present in C5, but not in C6. Rainbow scale indicates temperature range from 215K (violet) to 245K (red). Black indicates fill values.<br><br>Fill values in the atmospheric profiles causes failure of the LST retrieval developed by Simon Hook, so these LST retrievals are not made for granules where any profile levels are all fill. |
| PM_MOD_21265 | 2021-09-21 | 2021-10-12 | Note | Terra SSR reset, 2021.265 (9/22/21) The Solid State Recorder (SSR) Reset is currently scheduled to start DOY 265 (9/22/21) at 11:00z and is expected to go into early DOY 266 (9/23/21). During the activity SSR Science Data Record will be disabled and instrument science data will not be captured. The FOT will re-enable science data record once all requisite activities are completed. The successful resetting of the onboard SSRs will restore all the Terra MODIS PWA that were previously lost due to successive failures. <br><br>Links to the respective PWA failure notes are listed here: <br><br><A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=50"> 2019.179 (06.28.19)</A><br><A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=51"> 2019.242 (08.30.19)</A><br><A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=59">2020.279 (10.05.20)</A><br><A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=61">2021.179 (06.28.21)</A><br><A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=61">2021.180 (06.29.21)</A><br><br><br><br><b><center>************************************************ <p style="color:red">Terra SSR reset: UPDATE 10.12.21</p> ************************************************</b></center><br><br>Terra FOT successfully performed the solid-state recorder (SSR) reset on Sept 22, 2021. Science data acquisition was disabled between 2021.265 11:14:14 - 2021.265 22:53:58. However, due to the unavailability of Terra altitude and ephemeris files, MODAPS has a larger gap in the production from <b>2021.265 11:05 - 2021.266 00:05</b>. The data gaps from this event can be observed in the <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=244"> NRT.</A> Example images showing the data gap in the operational C6 archive are posted below. The global browse images show a large gap over portions of Europe and Africa in the daytime orbits, which extend to the Western hemisphere. The night time orbits shown in the MOD02 L1B Thermal band 21, the data gap can be observed over most of the Eastern hemisphere and Africa. The MODIS instrument continued to be in science mode and nominal operations through and after this activity. Initial assessment from FOT suggests that all the PWAs are now operational. Additionally, the daytime data collection schedule has been adjusted back to its previous nominal schedule. Starting on DOY 2021269-00:00 (09.26.21) the Terra day/night coverage has been restored to earlier 50/50 ratio following the successful SSR reset. More information on this can be found<A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=62"> here.</A><br><br><br><br> |
| PM_MOD_21264 | 2021-09-21 | 2022-12-05 | Note | Terra Constellation Exit Users of MODIS Science data products are requested to note that MODIS Terra is scheduled to exit the Morning Constellation of Earth Science satellites by October, 2022. Because of onboard fuel shortage, the last of Terra mission maneuver was done on February 27, 2020 to maintain the mean local time (MLT) of 10:30 AM. Thereafter, Terra has been drifting slowly from its MLT and will reach and exceed 10:15 AM MLT by October 2022, when it will make the constellation exit with a lowered orbit altitude of 694kms. More information in this regard can be found <A href="https://modis.gsfc.nasa.gov/news/individual.php?news_id=100378"> here</A> and<A href="https://terra.nasa.gov/about/terra-orbital-drift#:~:text=The%20Constellation%20Exit%20lowers%20the,to%20an%20uncontrolled%20de%2Dorbit."> here.</A><br><br>Please note that this does not indicate the end of life for Terra mission and Terra is expected to remain operational for at least another 5 more years and NASA SIPS will continue to produce and distribute science quality data through Fall of 2025. There may be some limited impact on the science data because of the changing MLT and the lowering of orbital altitude but overall, it is not expected to have any major impact on the science data quality.<br><br>We will continue to provide further updates in this regard as we get further inputs from the different land science teams.<br><br><br><br><br><b><center>************************************************ <p style="color:red">Terra Constellation Exit: UPDATE 12.05.22</p> ************************************************</b></center><br><br>C61/Terra post-CEM reprocessing: The recent Terra lunar calibration results indicated significant changes of cross-talk effects to some detectors in PV LWIR bands (bands 27-30) after the Constellation Exit Maneuver (CEM). MCST recommends to reprocess the Terra C6.1 L1B data (2022/296, 2200 onwards) after the CEMs using the updated LUT delivery, V6.2.2.81. The same L1B LUTs that resolves this drift in the PV-LWIR cross-talk has been operational in the C61 forward processing stream, starting 2022-11-22 (DOY 2022/326). Based on MCST's recommendation, following the CEMs, Terra L1Bs, LST (MOD21*) and L2 atmospheric products will be reprocessed for the period 2022-10-23 (DOY 2022/296) thru 2022-11-21 (DOY 2022/325 included).<br><br><br><br><br><b><center>************************************************ <p style="color:red">Terra Constellation Exit: UPDATE 11.04.22</p> ************************************************</b></center><br><br>The Terra MODIS instrument is operating in nominal status and all Terra MODIS operational production for C6 and C61 has resumed starting on 10.23.22 (2022.296) at 22:35 UTC.<br><br><br><br><br><b><center>************************************************ <p style="color:red">Terra Constellation Exit: UPDATE 10.28.22</p> ************************************************</b></center><br><br>All Terra NRT data production from NASA LANCE has resumed as of October 28 at 00:00, following a prolonged outage because of two successive Constellation Exit Maneuvers (CEM) that were performed on October 12 and 19 respectively.Following the CEMs, the space and nadir view doors were opened on October 21, and the MODIS formatter resumed nominal day/night mode operations from October 22. All instrument temperatures had attained their nominal values by October 23. Assessments carried out by the MODIS validation team now indicates nominal performance and no major cause for concerns, barring slight gain changes that have been noticed for some of the SWIR bands (mainly for Band 5), and possibly slight change in cross-talk behaviors for some of the PV-LWIR detectors.<br><br>Users are being warned, not to use any Terra MODIS data products that may be available from nrt3 or nrt4 servers, prior to October 28 (DOY 301) resumption of Terra data from LANCE NRT, as all instrument status and performance may not have been nominal till then.<br><br>MODAPS is also expected to resume the operational forward processing of all MODIS Terra products, shortly.<br><br><br><br><br><br><b><center>************************************************ <p style="color:red">Terra Constellation Exit: UPDATE 10.25.22</p> ************************************************</b></center><br><br>Over the past few days, the MODIS IOT commanded the MODIS instrument back into nominal science mode after a 24-hour outgas period. The return to nominal command was issued at 2022/294 19:59:10z. The nadir and SV doors have been opened and the CFPAs and BB are in the process of returning to their nominal temperatures. These temperatures will take a few days to settle, after which time MCST will begin to evaluate the performance of each band. The Day/Night formatter has returned to normal starting on day 295, with the first granule with daytime data starting at 2022295.0040.<br><br><br><br><br><b><center>************************************************ <p style="color:red">Terra Constellation Exit: UPDATE 10.20.22</p> ************************************************</b></center><br><br>Terra Constellation Exit Maneuver (CEM) #2 was completed successfully on October 19. The loss of pointing accuracy times are: LOPA: 2022/292 19:03:45-22:48:44. Starting today, October 20, MODIS IOT will begin commanding to return the sensor back to nominal operations. Following that, MCST will begin to assess the instrument status next week. MODAPS will resume all Terra data production, once confirmation and updated LUTs are received from MCST.<br><br><br><br><br><b><center>************************************************ <p style="color:red">Terra Constellation Exit: UPDATE 10.12.22</p> ************************************************</b></center><br><br>The first of the Terra Constellation Exit Maneuver (CEM) was completed successfully on October 12, between 14:20:54 - 15:05:10. All Terra MODIS data production and distribution are to remain on-hold from both STD and NRT streams, following the last Terra Constellation Exit Maneuver (CEM) on October 19, for at least a week, till around October 26 or slightly more. During this time, the MODIS calibration team (MCST) will review all instrument performance and will most likely provide updated LUTs to address any drifts or issues. Following the confirmation of all Terra MODIS instrument status and the delivery of updated LUTs, MODAPS will resume all Terra MODIS data production from both, STD and NRT streams and may also reprocess some of the days following the end of the last CEM on October 19, with the updated LUTs.<br><br><br><br><br><b><center>************************************************ <p style="color:red">Terra Constellation Exit: UPDATE 09.26.22</p> ************************************************</b></center><br><br>The initial Terra Constellation Exit Maneuver (CEM) is scheduled for October 12, 2022, around 7:30 am EDT. The CEM will be carried out through two successive maneuvers, on October 12 and 19, respectively. Users should expect Terra MODIS data outage, starting October 10 till October 19. Following the last maneuver on October 19, an outgas procedure will be performed and all things are expected to stabilize within 48 hours after that. MCST will monitor the telemetry and an update will be provided when all instruments approach their nominal operating temperatures. Users should exercise caution, while using the Terra MODIS data between October 19 - October 21, as all instruments are still recovering, after the outage. Special LUT deliveries are expected to account for any gain changes that may occur in the instrument upon recovery.<br><br><br><br><br><b><center>************************************************ <p style="color:red">Terra Constellation Exit: UPDATE 09.20.22</p> ************************************************</b></center><br><br>The initial Terra Constellation Exit Maneuver (CEM) is scheduled for October 12, 2022, around 7:30 am EDT. The CEM will be carried out through two successive maneuvers, on October 12 and 19, respectively. All science data acquisition will remain suspended during, between, and following these two successive maneuvers, for a period of about 10 days, as MODIS will remain in a "CEM configuration" mode between the CEMs, where SV and EV doors will remain closed, Blackbody will be turned off and the SMIR and LWIR focal plane/heaters will be turned off as well. Post CEM, some more time will be needed to bring all instruments back to their nominal status. Post-CEM calibrations will be performed over the following weeks and LUT updates will occur as needed. MODIS data users of both NRT and operational processing streams are requested to take note of this and expect data outage for at least 10 days, starting October 12. This note will be further updated after the event, once all instruments are back to their nominal status and both NRT / operational production has resumed.<br><br><br><br> |
| PM_MOD21_21200 | 2021-07-19 | 2021-07-19 | Note | Differences in heritage MODIS LST (MxD11) compared to MXD21 / VNP21 Users of the different MODIS and VIIRS LST products, generated by MODAPS and NASA LandSIPS, may notice more occurrences of extreme high temperature outliers in the MxD21 (C6/C61) and the VNP21 (C1 S-NPP VIIRS) products, compared to the heritage MxD11 LST products. One reason for this is a tighter filtering for clouds employed in the MxD11 code, for daily and n-day products, that is based on a temporal analysis of LST over cloudy areas. The MxD11 code could also be using some additional dust removal filter that we are not fully certain of at this time.<br><br>In order to alleviate this issue in the MxD21 and VNP21 products from C6/C61 (MODIS) and C1 (S-NPP VIIRS), the MxD21 science team recommends using a combination of the existing QC bits, emissivity values and estimated product errors, to confidently remove bad pixels from analysis. For more details regarding this, the users can refer to<A href="https://landweb.modaps.eosdis.nasa.gov/data/userguide/MOD21_dust_QC_examples.pdf"> this documentation.</A><br><br> |
| PM_MOD_21193 | 2021-07-14 | 2021-07-14 | Note | Data loss Due to Contact Errors 2021.193 On 07.12.21 (2021.193) the Terra MODIS instrument experienced a data loss during a daytime orbit over Australia. Due to weather, the relay satellites TDE and TDS were unavailable starting with the 01:16:00z TDS contact. Blind acquisitions were scheduled in order to attempt to recover data. After the blind acquisitions were performed, there was still missing MISR and MODIS data. Currently, geolocation and L1B reflectance and thermal bands are impacted for granules 00:50 through 01:00 inclusive. At this time it is unclear if this data loss is recoverable, this note will be updated accordingly as more information becomes available. Below are the data segment start and stop times for the lost MODIS APID 64 data.<br><br>2021-193-00:51:40.889666 - 2021-193-01:01:12.543435 <br>2021-193-01:01:12.543435 - 2021-193-01:01:12.543435 <br>2021-193-01:01:13.834212 - 2021-193-01:01:14.020585<br><br><br><b>************************************************ <p style="color:red">UPDATE 07.19.21: The MODIS TERRA data loss has been finalized for this event, this data is not recoverable: 2021.193/00:51:40 - 193/01:01:14.</p> ************************************************</b></center><br> |
| PM_MOD_21181 | 2021-07-12 | 2021-07-12 | Note | MODIS PWA-47 anomaly 2021.180 On June 29, 2021 (DOY 180), Terra experienced another PWA failure (PWA-47), affecting the supersets of 92/93, bringing down the total number of MODIS SS to 26. The failed MODIS supersets from PWA 47 were successfully removed and operations were completed during the contact (181/01:55:09 - 02:05:44z) at 01:58z. Detailed information on the data loss and most recent information can be found here:<A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=61"> MODIS PWA-47 anomaly.</A><br><br> |
| PM_MOD_21180 | 2021-07-06 | 2021-07-06 | Note | MODIS Data loss due to MISR PWA-40 2021.180 On June 28th, 2021 (2021.179) a PWA #40 occurred in the MISR buffer. On the TDS contact (180/02:17:00 - 02:35:00z), the failed supersets were successfully removed from the MISR buffer by first temporarily disabling science recording. After the superset removal, the OCE reported data gaps in MODIS corresponding to when science recording was disabled. This resulted in data loss of the Terra MODIS instrument from 180/02:22:21 - 180/02:30:47 as mainly due to disabling of science data acquisition during the removal of PWA-40, allocated for MISR onboard recording. The L1B emissive band global browse image below shows this data loss in the 02:00 nightime orbit over the Caribbean and North America, highlighted by the red box. This data is not recoverable. The remaining data gaps are associated with the <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=61"> MODIS PWA-47 anomaly</A>, which occurred on the same day. <br><br> |
| PM_MOD_21010 | 2021-01-11 | 2021-01-12 | Note | Data loss due to a contact error 2021.010 On January 10th, 2021 (2021.010) a contact error occurred, which resulted in a nonrecoverable data loss for Terra MODIS. The unrecoverable data loss impacts time 2021.010 (03:12:27 to 03:18:00), which occurred during a night time orbit over South America. The L1B emissive bands and geolocation were reviewed and granules 03:10 and 03:15 were directly impacted but otherwise found to be free of artifacts or corrupt data. Processing has been closed and the data is not recoverable. Below, the first image an example global browse, which shows the data loss over South America. The second image is a spatial subset of the global browse image showing South America, where the gap occurs. The last two images shows the L1B emissive band and geolocation information for granule 03:15.<br><br> |
| PM_MOD_20280 | 2020-10-13 | 2021-09-29 | Note | Day/Night coverage ration changed to 40/60 On DOY 2020.279 (10.05.20) <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=61"> MODIS Terra experienced a PWA failure </A> that affected the PWA-41 (supersets 80 and 81), bringing down the total number of MODIS PWA to 14 with only 28 supersets. Given this, there is an increased chance of buffers being filled and data overwritten, resulting in unscheduled and unrecoverable data loss. So, FOT and MODIOT have decided to change the day/night coverage ratio from current 50/50 to 44.2/55.8 to minimize the overflow of onboard buffers. This ratio change occurred on October 7th (2020.281) at 20:00z. Due to this change there is an observed reduction in the overall Terra daytime coverage, specifically at the end of orbits in the northern latitudes. Below is a global browse image of DOY 2020.280, prior to the implementation of the ratio change. The second image on the right shows DOY 2020.282, where the ratio change has been implemented for the full day, and has impacted retrieval over high latitude. In this second image you can observe the reduced daytime coverage over Greenland and portions of Northern Russia as well as North America and Alaska. For comparison, the same DOY 282 from 2019 is shown in the third image, which verifies the difference is not due to seasonal affect.<br><br> |
| PM_MOD_20182 | 2020-10-06 | 2020-10-06 | Note | MODIS PWA-41 anomaly 2020.279 On DOY 2020.279 (10.05.20) MODIS Terra experienced a PWA failure that affected two more PWA-41 (supersets 80 and 81), bringing down the total number of MODIS SS to 28. The current PWA failure event happened around 15:21:12z. FOT was able to move the two corrupt supersets to the bad superset list at the contact on 2020.280/03:28:00 - 03:46:00z. Science recording was disabled at 03:32:56 to handle the moving of the supersets and re-enabled at 03:41:56z. Detailed information on the data loss and most recent information can be found here:<A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=61"> MODIS PWA-41 anomaly.</A><br><br> |
| PM_MOD_22314 | 2022-11-14 | 2022-11-14 | Note | Data loss 2022.314 (11.10.22) On November 10th, 2022 (2022.314) a nonrecoverable data loss occurred for Terra MODIS. The unrecoverable data loss impacts time 2022.314/01:47:48 - 314/01:52:37, which occurred during a night time orbit over South America. The L1B emissive bands and geolocation were reviewed and granules 01:45 and 01:50 were verified to contain this data loss. Processing has been closed and the data is not recoverable. The two images below shows the L1B emissive band and geolocation information for granule 01:45.<br><br> |
| PM_MOD_20279 | 2020-10-06 | 2021-07-06 | Note | PWA data loss: 2020.279, 2021.180 <br><br><br><br><b><center>************************************************ <p style="color:red">PWA-41: UPDATE 10.06.20</p> ************************************************</b></center><br>On DOY 2020.279 (10.05.20) MODIS Terra experienced a PWA failure that affected two more PWA-41 (supersets 80 and 81), bringing down the total number of MODIS SS to 28. The current PWA failure event happened around 15:21:12z. FOT was able to move the two corrupt supersets to the bad superset list at the contact on 2020.280/03:28:00 - 03:46:00z. Science recording was disabled at 03:32:56 to handle the moving of the supersets and re-enabled at 03:41:56z.<br><br>Terra MODIS shows partial to full science data loss on 2020.279 for <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=61"> NRT</A> and C6/C61 forward production over the following time ranges (15:05, 16:45, 18:30), where the data could not be played back because of recording on the faulty PWA-41. The image below for DOY 2020.279, shows these gaps across the globe. On day 2020.280 science data acquisition was disabled temporarily between 03:32:56-03:41:56 to move the bad supersets to the bad superset list. The global browse image for DOY 2020.280 is provided below. The 2020.280 global browse image shows the L1B B29 night time orbits and additional missing data for periods for 00:00-00:30, 01:20-01:55, 03:25-03:45, and 21:30-21:45.<br><br>**** NOTE: 10.27.20 **** MODAPS has filled in the data to the best possible extent, based on additional L0 from the MODIS Direct Broadcast (DB) stations. The Terra Data Loss has been finalized from the PWA anomaly. MODIS:2020.279 (15:04:02 - 15:08:36, 16:47:03 - 16:51:37, 18:30:02 - 18:34:36, 20:13:01 - 20:17:34, 21:56:00 - 22:00:33, 23:38:59 - 280/00:31:41) have been lost due to this event, and are not recoverable. Additionally, DOY 2020.280 granules 01:30, 01:35, 01:50, 01:55, 02:00, 03:00, 21:35 and 21:40 were found to contain impacts to geolocation information.<br><br> |
| PM_MOD_20260 | 2020-09-18 | 2020-09-18 | Note | Data loss due to contact error 2020.260 On September 16th, 2020 (2020.260) a 5 minute data gap occurred on Terra MODIS due to a contact error from 02:30:12 - 02:35:00z. Attempts to recover this data loss were unsuccessful. Processing has been closed and the data is not recoverable. The gap in granule 02:30, occurred during a daytime orbit over Arctic. An example of the impact to the in the L1B geolocation and reflectance layers will be posted when the data are available to review.<br><br> |
| PM_MOD11_20160 | 2020-06-08 | 2020-06-08 | Note | Oct.2013 - Dec.2013, MOD11B1 production ahead of MYD11B1 The MODIS process, responsible for producing the MOD11B1 and MYD11B1 products, is designed to run almost simultaneously for both MODIS Terra and Aqua. This provides near continuous measurements of the Atmosphere state and cloud cover. However, this synchronization was disrupted for a brief period during the C61 processing. From the middle of October 15th, 2013 (2013.288) to middle of December 15th, 2013 (2013.349), the MOD11B1 production moved further ahead of MYD11B1. This discrepancy could possibly lead to slight inconsistencies in the MxD11B1 LST from this period. Overall, the initial review of the MxD11B1s from this period shows the product as good quality. However, users are advised to use caution and apply their own judgment while using the MOD11B1 from this specific period.<br><br><br><br> |
| PM_MOD_20120 | 2020-04-29 | 2020-04-29 | Note | Maneuver review and various Data gap issues All maneuver periods for both MODIS Terra and Aqua instruments are reviewed by LDOPE in detail for geolocation accuracy and overall data quality. In cases, where a geolocation shift or corrupt data is detected, LDOPE will notify MODAPS to hide or remove specific maneuver time periods of granules from L1B and downstream data production. These periods are also recorded on the Maneuver page for<A href="https://landweb.modaps.eosdis.nasa.gov/maneuver"> both Terra and Aqua.</A> The sections below provide descriptions and links to detailed information regarding common data gap and outage issues observed and reviewed by LDOPE.<br><br><b><br>MODAPS Data Outage Pages:</b><br>Users can reference a general list of MODIS Data Outage dates and times, which is maintained at MODAPS for the entire TERRA and AQUA missions: The following MODAPS table outlines major data outage periods since the start of the missions. Information in these links lists all <A href="https://modaps.modaps.eosdis.nasa.gov/services/production/outages_terra.html"> TERRA</A> and <A href="https://modaps.modaps.eosdis.nasa.gov/services/production/outages_aqua.html"> AQUA</A> data outages.<br><br><br><b>Data gaps due to poor geolocation accuracy and overall data quality during maneuver periods:</b><br>Information in these links lists all <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=57"> TERRA</A> and <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=156"> AQUA</A> maneuver dates and granules (Start / End times) where granules have been hidden due to poor geolocation accuracy or corrupt data.<br><br><br><b>Data loss due to contact errors:</b> <br>These events occur throughout the missions and are reviewed on an individual basis for<A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=55"> TERRA</A> and <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=151"> AQUA</A> as they occur.<br>In many cases, these and other types of data outages are not often recoverable and a note with detailed impacts on the data and events are posted in the known issues page that apply to all MODIS <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=57"> TERRA</A> and AQUA</A> land products.<br><br><br><b>The Semi-annual Night-time-day-mode calibration activity:</b> <br>These are rolling notes for <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=52"> TERRA</A> and <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=152"> AQUA</A> that detail a routine calibration activity, which happens every six months and includes a portion of nighttime time data acquired in day mode and then a portion of day time data acquired in night mode. These nighttime day mode activities can sometimes be accompanied by instrument Roll Maneuver too.<br><br><br> |
| PM_MOD_20119 | 2020-04-21 | 2020-04-21 | Note | TERRA Maneuver List The list below identifies all TERRA maneuver dates and granules (Start / End times) where granules were hidden due to poor geolocation accuracy. For more details please refer back to<A href="https://landweb.modaps.eosdis.nasa.gov/maneuver"> the Maneuver table.</A> <br>Please click <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=58">here</A> to go back to the main LDOPE Maneuver QA note.<br><br><p><PRE>Year-Day Date Start Time (UTC)/ End Time (UTC)<br><br>2020<br>2020-058 February 27, 2020 15:10 16:00 <br>2020-051 February 20, 2020 15:00 15:45 <br>2020-023 January 23, 2020 01:25 03:55 <br><br>2019 <br>2019-345 December 11, 2019 14:55 15:45 <br>2019-323 November 19, 2019 15:30 16:20 <br>2019-291 October 18, 2019 15:30 16:15 <br>2019-290 October 17, 2019 16:25 17:15 <br>2019-262 September 19, 2019 16:15 17:00 <br>2019-262 September 19, 2019 01:15 02:00 <br>2019-255 September 12, 2019 16:00 16:40 <br>2019-193 July 12, 2019 19:00 19:50 <br>2019-178 June 27, 2019 16:25 17:20 <br>2019-102 April 12, 2019 04:20 05:20 <br>2019-065 March 06, 2019 14:50 17:25 <br>2019-057 February 26, 2019 06:40 07:30 <br>2019-031 January 31, 2019 17:35 18:25 <br><br>2018 <br>2018-360 December 26, 2018 16:00 16:10 <br>2018-339 December 05, 2018 14:50 18:40 <br>2018-305 November 01, 2018 16:15 17:05 <br>2018-298 October 25, 2018 16:10 17:00 <br>2018-222 August 10, 2018 22:20 22:35 <br>2018-213 August 01, 2018 19:00 19:30 <br>2018-053 February 22, 2018 15:50 17:25 <br><br>2017 <br>2017-348 December 14, 2017 14:50 15:35 <br>2017-292 October 19, 2017 15:35 16:30 <br>2017-282 October 09, 2017 16:40 17:00 <br>2017-186 July 05, 2017 15:55 17:35 <br>2017-180 June 29, 2017 13:25 15:25 <br>2017-145 May 25, 2017 16:50 17:15 <br>2017-102 April 12, 2017 14:15 16:30 <br>2017-047 February 16, 2017 15:20 16:05 <br><br>2016 <br>2016-294 October 20, 2016 13:25 16:30 <br>2016-235 August 22, 2016 10:40 12:25 <br>2016-105 April 14, 2016 13:15 16:40 <br>2016-071 March 11, 2016 14:15 17:20 <br>2016-063 March 03, 2016 13:20 18:35 <br><br>2015 <br>2015-351 December 17, 2015 15:20 18:45 <br>2015-301 October 28, 2015 13:30 18:30 <br>2015-167 June 16, 2015 00:10 02:35 <br>2015-112 April 22, 2015 13:00 15:40 <br>2015-069 March 10, 2015 17:35 17:40 <br>2015-063 March 04, 2015 13:25 15:55 <br>2015-056 February 25, 2015 13:35 17:35 <br>2015-050 February 19, 2015 14:20 17:30 <br><br>2014 <br>2014-346 December 12, 2014 14:50 17:50 <br>2014-315 November 11, 2014 08:30 10:15 <br>2014-302 October 29, 2014 13:25 18:00 <br>2014-203 July 22, 2014 14:35 18:05 <br>2014-115 April 25, 2014 14:10 17:45 <br>2014-080 March 21, 2014 12:45 15:05 <br>2014-073 March 14, 2014 15:05 18:40 <br>2014-057 February 26, 2014 13:00 17:20 <br>2014-043 February 12, 2014 13:10 16:15 <br>2014-031 January 31, 2014 14:05 17:40 <br><br>2013 <br>2013-345 December 11, 2013 14:20 17:20 <br>2013-297 October 24, 2013 15:25 18:05 <br>2013-296 October 23, 2013 16:50 18:15 <br>2013-290 October 17, 2013 13:20 17:15 <br>2013-283 October 10, 2013 13:25 16:35 <br>2013-230 August 18, 2013 10:05 12:50 <br>2013-207 July 26, 2013 18:20 19:40 <br>2013-199 July 18, 2013 13:45 16:10 <br>2013-119 April 29, 2013 20:50 22:00 <br>2013-057 February 26, 2013 13:50 17:05 <br><br>2012 <br>2012-354 December 19, 2012 17:05 19:25 <br>2012-314 November 09, 2012 13:10 15:55 <br>2012-286 October 12, 2012 13:55 17:10 <br>2012-279 October 05, 2012 13:45 16:45 <br>2012-279 October 05, 2012 01:00 02:45 <br>2012-249 September 05, 2012 07:35 09:15 <br>2012-222 August 09, 2012 13:45 16:05 <br>2012-189 - 2012-190 July 07, 2012 - July 08, 2012 22:45 00:40 <br>2012-158 June 06, 2012 13:45 16:40 <br>2012-096 April 05, 2012 15:55 19:55 <br>2012-054 February 23, 2012 14:25 17:40 <br>2012-032 February 01, 2012 13:25 16:50 <br><br>2011 <br>2011-299 October 26, 2011 13:55 16:55 <br>2011-292 October 19, 2011 13:20 16:50 <br>2011-260 September 17, 2011 09:15 10:55 <br>2011-230 August 18, 2011 15:35 16:55 <br>2011-171 June 20, 2011 06:45 08:40 <br>2011-166 June 15, 2011 14:55 17:55 <br>2011-019 January 19, 2011 16:10 19:00 <br><br>2010 <br>2010-301 October 28, 2010 14:00 17:45 <br>2010-300 October 27, 2010 17:00 19:25 <br>2010-294 October 21, 2010 13:45 17:45 <br>2010-223 August 11, 2010 13:35 17:45 <br>2010-152 June 01, 2010 15:30 18:00 <br>2010-055 February 24, 2010 14:30 17:55 <br>2010-004 January 04, 2010 15:55 18:00 <br><br>2009 <br>2009-286 October 13, 2009 13:10 17:45 <br>2009-280 October 07, 2009 14:30 17:20 <br>2009-252 September 09, 2009 05:45 07:45 <br>2009-190 July 09, 2009 14:25 17:35 <br>2009-044 February 13, 2009 13:30 16:50 <br><br>2008 <br>2008-322 November 17, 2008 03:45 05:25 <br>2008-311 November 06, 2008 16:25 18:40 <br>2008-297 October 23, 2008 14:55 18:05 <br>2008-263 September 19, 2008 10:35 12:15 <br>2008-213 July 31, 2008 17:30 19:25 <br>2008-084 March 24, 2008 15:05 17:45 <br>2008-058 February 27, 2008 14:00 17:15 <br><br>2007 <br>2007-273 September 30, 2007 16:35 18:20 <br><br>2006 <br>2006-343 December 09, 2006 08:30 10:05 <br>2006-340 December 06, 2006 17:25 19:50 <br>2006-325 November 21, 2006 14:40 17:55 <br>2006-318 November 14, 2006 14:35 17:50 <br>2006-313 November 09, 2006 16:20 18:00 <br>2006-290 October 17, 2006 14:45 17:25 <br>2006-285 October 12, 2006 16:00 18:40 --WAIVED OFF-- <br>2006-144 May 24, 2006 16:30 18:45 <br>2006-018 - 2006-019 January 18, 2006 - January 19, 2006 21:35 00:15 <br><br>2005 <br>2005-349 December 15, 2005 14:20 17:30 <br>2005-347 December 13, 2005 14:30 17:35 <br>2005-341 December 07, 2005 13:35 16:50 <br>2005-324 November 20, 2005 15:00 16:40 <br>2005-265 September 22, 2005 05:00 07:00 <br>2005-258 September 15, 2005 16:25 19:00 <br>2005-235 August 23, 2005 16:35 18:00 <br>2005-206 July 25, 2005 06:50 08:20 <br>2005-177 June 26, 2005 00:40 02:25 <br>2005-160 June 09, 2005 18:20 20:45 <br>2005-059 February 28, 2005 17:50 19:55 <br>2005-054 February 23, 2005 20:00 23:05 <br><br>2004 <br>2004-366 December 31, 2004 13:25 15:05 <br>2004-328 November 23, 2004 18:10 20:50 <br>2004-309 November 04, 2004 13:15 16:35 <br>2004-302 October 28, 2004 13:25 16:30 <br>2004-300 October 26, 2004 13:50 17:00 <br>2004-277 October 03, 2004 01:55 04:00 <br>2004-247 September 03, 2004 09:55 11:40 <br>2004-176 June 24, 2004 18:20 20:05 <br>2004-097 April 06, 2004 17:00 20:00 <br>2004-028 January 28, 2004 16:50 19:30 <br><br>2003 <br>2003-347 December 13, 2003 17:05 19:50 <br>2003-304 October 31, 2003 16:40 19:40 <br>2003-288 October 15, 2003 07:35 10:15 <br>2003-228 August 16, 2003 18:20 21:00 <br>2003-218 August 06, 2003 13:55 17:00 <br>2003-212 July 31, 2003 14:30 17:35 <br>2003-210 July 29, 2003 13:05 16:10 <br>2003-203 July 22, 2003 19:30 22:30 <br>2003-199 July 18, 2003 02:15 04:55 <br>2003-169 June 18, 2003 13:30 16:15 <br>2003-120 April 30, 2003 17:45 20:45 <br>2003-104 - 2003-105 April 14, 2003 - April 15, 2003 20:25 00:00 <br>2003-081 March 22, 2003 06:10 08:50 <br>2003-065 March 06, 2003 18:15 20:45 <br>2003-022 January 22, 2003 14:50 16:10 <br>2003-016 January 16, 2003 10:40 21:00 <br>2003-007 January 07, 2003 17:50 20:10 <br><br>2002 <br>2002-358 December 24, 2002 06:10 07:20 <br>2002-269 September 26, 2002 14:30 15:20 <br>2002-219 August 07, 2002 17:40 19:40 <br>2002-210 July 29, 2002 04:25 05:35 <br>2002-180 June 29, 2002 12:25 13:40 <br>2002-170 June 19, 2002 16:55 19:30 <br>2002-128 May 08, 2002 18:05 20:45 <br>2002-100 April 10, 2002 19:30 21:55 <br>2002-072 March 13, 2002 18:45 20:20 <br>2002-064 March 05, 2002 14:35 16:40 <br>2002-057 February 26, 2002 14:40 16:10 <br>2002-037 February 06, 2002 14:25 17:25 <br>2002-032 February 01, 2002 18:45 21:55 <br>2002-009 January 09, 2002 18:40 21:40 <br>2002-003 January 03, 2002 09:40 12:50 <br><br>2001 <br>2001-352 December 18, 2001 18:40 21:40 <br>2001-339 December 05, 2001 02:00 05:15 <br>2001-319 November 15, 2001 18:35 21:50 <br>2001-309 November 05, 2001 16:35 19:35 <br>2001-280 October 07, 2001 05:35 08:50 <br>2001-275 October 02, 2001 17:25 21:30 <br>2001-250 September 07, 2001 18:25 21:40 <br>2001-221 August 09, 2001 04:00 07:15 <br>2001-128 May 08, 2001 18:50 21:50 <br>2001-095 April 05, 2001 17:40 20:40 <br>2001-043 February 12, 2001 05:50 09:05 <br>2001-013 January 13, 2001 15:45 18:55 <br><br>2000 <br>2000-350 December 15, 2000 06:30 09:35 <br>2000-340 December 05, 2000 17:35 20:35 <br>2000-306 November 01, 2000 17:40 21:10 <br>2000-291 October 17, 2000 13:25 18:20 <br>2000-278 October 04, 2000 16:00 19:30 <br>2000-262 September 18, 2000 04:00 07:15 <br>2000-203 July 21, 2000 10:35 13:55 <br>2000-173 - 2000-174 June 21, 2000 - June 22, 2000 20:10 02:45 <br>2000-172 June 20, 2000 17:15 20:05 <br>2000-167 June 15, 2000 16:10 23:15 <br>2000-104 April 13, 2000 12:30 22:15 <br>2000-103 April 12, 2000 18:20 22:20 <br>2000-084 March 24, 2000 15:20 22:30 <br>2000-076 - 2000-077 March 16, 2000 - March 17, 2000 14:05 01:35 <br>2000-075 - 2000-076 March 15, 2000 - March 16, 2000 13:20 00:55</PRE><br><br> |
| PM_MOD09_20010 | 2020-04-10 | 2020-04-27 | Note | MODIS aerosol quantity flag in error in C6, corrected in C61 The aerosol quantity flag in the C6 MODIS Surface Reflectance product (MOD09/<A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=174">MYD09</A>) may have been in error and may not have correctly presented the spatial distribution of different aerosol quantities (low, average and high) over the globe. This is more relevant for areas with brighter surfaces and high-aerosols. This has been corrected in C61, using a new approach that is also consistent across the two sensors, MODIS Terra/Aqua and VIIRS S-NPP. Please note that the flag value corresponds to three level quantification of the uncertainty in aerosol correction to the surface reflectance. The new approach adopted in the C61 product only corrects the quantification of the aerosol correction impact and does not change the retrieved land surface reflectance (LSR) values. Any impact from this, on the downstream L3 dailies are minimal and are seen to produce small differences in the different "n-day" products that are dependent on LSR. For a more detailed discussion on the changes and impact on different downstream products please <A href="https://landweb.modaps.eosdis.nasa.gov/data/userguide/LSRHighAerosolFlagFinal.pdf">refer to the following document.</A><br><br>Examples below show RGB composite images of surface reflectance bands 1, 4 and 3 with areas flagged as high aerosol removed from the images: image on the left is from the C61 surface reflectance product generated using the old approach to flag the aerosol (as in the C6 products) and the image on the right is from the C61 surface reflectance product generated using the new approach to flag the aerosol. Use of the new approach to flag aerosol results in fewer retrievals being flagged as high aerosol.<br><br><br> |
| PM_MOD02_20094 | 2020-04-03 | 2020-04-03 | Note | C61 Band 7 reflectance more accurate than C6 MODIS Terra was using the A-side electronics from the start of the mission till day 2000.304. On day 2000.305 the electronics was switched to B-side. As long as the A-side electronics was in use the detector 14 of Band 7, was classified as "Non-functional Detector". To alleviate this downstream MOD09 process would employ a destriper to interpolate the band values across the dead detector. But due to some error in the Collection 6 (C6) configuration file for this destriping the destriping for band 7 was not perfect. This has been corrected in Collection 6.1 and the band 7 reflectance in C61 is more accurate than C6 and is comparable to Collection 5 (C5). The PDF whose link has been provided below, documents this differences in band 7 reflectance values over several land calibration sites, between C5/C6 and C6.1.<a href="https://landweb.modaps.eosdis.nasa.gov/data/userguide/TimeSeries_Anamoly_v2.pdf" target=_blank>(link to PDF file)</a>.<br><br>For further reference with regard to the switch from A-side to B-side electronics the users are also encouraged to refer to<A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=75"> this additional QA note.</A><br><br><br> |
| PM_MOD_20089 | 2020-03-31 | 2020-03-31 | Note | Data loss due to buffer error 2020.089 On March 29th, 2020 (2020.089) a data gap occurred on Terra MODIS due to unknown errors in the MODIS buffer after a playback error. The impacted times are from 02:22:55 - 03:42:41. The data loss occurs during a daytime orbit over eastern China and a night time orbit over the Americas. Attempts to recover this data loss were unsuccessful. Processing has been closed and the data is not recoverable. Below is an example image, which shows the data gap during a daytime orbit over eastern Asia.<br><br> |
| PM_MOD_20033 | 2020-02-25 | 2020-02-25 | Note | Data loss due to contact error 2020.033 On February 2nd, 2019 (2020.033) a 5 second data gap occurred on Terra MODIS due to a contact error from 11:09:32z to 11:09:37z. Attempts to recover this data loss were unsuccessful. Processing has been closed and the data is not recoverable. Below is an example image form granule 11:05, which shows the data gap during a daytime orbit over Antarctica in the L1B geolocation and reflectance layers.<br><br> |
| PM_MOD10_20006 | 2020-01-06 | 2020-01-06 | Pending | M*D10CM code fails to identify cloud obscured and sea-ice covered inland water bodies The C6 M[O|Y]D10CM product fails to identify all inland water bodies. This primarily happens over the cloud obscured and sea-ice covered inland water bodies which are assigned a fill value of 255 instead of 254 that is meant for inland water bodies. The upstream MOD10C1 snow cover inputs have three possible values for inland water, 237 (clear view of inland water), 107 (ice covered inland water) or 250 (cloud obscured inland water). The problem of fill, over inland water bodies in M[O|Y]D10CM, appears to be the result of the MOD10CM process not checking specifically for the values of 107 and 250 when it makes the universal water mask. Pixels with these values fall through and are set to fill in the MOD10CM. Example below show MOD10CM, where values (250,107) associated with inland water are incorrectly classified. The science team is currently working on a fix to the code that will resolve this in the C61 MOD10CM process. |
| PM_MOD11_22318 | 2022-11-14 | 2022-12-05 | Closed | C6 MOD11 LST loss of retrieval The C6 MODIS Terra Day and Night Land Surface Temperature/Emissivity (MOD11*) daily LST products are showing loss of data retrieval in the L2 and L3 daily/CMG products. The issue is under investigation. The two images below show global browse images from C6 and C61 for October 27th, 2022 (2022.300). The image on the left shows a significant loss of LST retrieval in the C6 MOD11B1 product compared to the global browse image of C61 on the right. LDOPE is currently investigating this to determine the root cause of this issue and the impacted periods. This note will be updated as more information becomes available.<br><br><br> |
| PM_MOD11_20002 | 2020-01-02 | 2020-01-06 | Pending | blocky artifacts impacts LST L2/L3 retrieval The MXD11 LST L2 and L3 products occasionally show blocky artifacts in regions such as Africa and Australia during the daytime LST retrieval. The first example below shows the L2 LST product during a daytime orbit over Africa. The second image below shows another example over Australia from day 12.29.19. The issue is currently under investigation and the exact cause is not yet known. This note will be updated when more information becomes available. |
| PM_MOD11_20006 | 2020-01-02 | 2020-01-06 | Note | MOD11C1 Band 20 / 29 emissivity replication The MODIS Collection 6 (C6) daily heritage LST CMG product (MxD11C1) is known to have identical values for the band 20 and 29 emissivity (Emis_20/Emis_29 and Emis_20_night/Emis_29_night respectively) as the band 29 emissivity values are replicated as band 20 emissivity values. This was done to ignore the band 20 emissivity, most likely because of one or all of the following reasons: 1) the overall quality of MODIS band 20 radiance, 2) weak thermal signal from land and 3) residual errors, related to solar correction, in this band. This replication of emissivity values will also be seen in the downstream MxD11C2/C3 products that uses the MxD11C1 as inputs.<br><br>However, to avoid any confusion on the part of the user, the land science team has decided to address this in the Collection 6.1 of MODIS land products, where the Band 20 emissivity will reflect the actual band specific values and will not be copied over from Band 29 anymore. This will be accurately reflected in the MxD11C2/C3 products as well.<br><br><br><br> |
| PM_MOD_19336 | 2019-12-02 | 2019-12-02 | Note | Maneuver review and reprocessing issues All maneuver periods for both MODIS Terra and Aqua instruments are reviewed by LDOPE in detail for geolocation accuracy and overall data quality. In cases, where a geolocation shift or corrupt data is detected, LDOPE will notify MODAPS to hide or remove specific maneuver time periods of granules from L1B and downstream data production. These periods are also recorded on the Maneuver page for<A href="https://landweb.modaps.eosdis.nasa.gov/maneuver"> both Terra and Aqua.</A> In rare cases, the information LDOPE provides to MODAPS maybe incomplete and or incorrect. In these cases, LDOPE will double check the maneuver period and send corrected date / time information to MODAPS. This may result in multiple re-processing of all dailies for the given day as well as all associated n-day products. As a result, the users may notice duplicate versions of the same product in the DAACs. This note will document all such cases and the users are advised to pick up the product(s) with the latest production times, in all such cases.<br><br>1. On September 19th, 2019 (2019.262) the Terra instrument experienced a MODIS Roll maneuver #200. During the review of this maneuver period, LDOPE retracted an earlier reported time of maneuver impact that was wrong and a second corrected version of impacted date and times was notified to MODAPS (01:15 - 01:55). Production, reran this day, which may have caused duplicate downstream dailies for day 2019262 and the associated 8-day products from day 2019257 to be temporarily archived at the DAACs. This issue has been resolved, however, users should verify that they have the correct version of this data based on the most recent production time.<br><br> |
| PM_MOD_19326 | 2019-11-25 | 2019-11-25 | Note | Data loss due to contact error 2019.326 On November 22nd, 2019 (2019.326) the MOD02SSH (L1B) data received for C6 processing had no data between 326/02:16:32 - 326/02:22:02. This gap is due to a Terra data loss event from a contact error. Processing has been closed and the data is not recoverable. Below is an example image of TERRA L1B, B32 nighttime browse image from data day 2019.326 (11/22/2019), which shows the data gap during an night time orbit over the South America.<br><br> |
| PM_MOD_19305 | 2019-11-05 | 2023-10-18 | Note | Semi-annual Night-time-day-mode calibration activity Rolling Note A routine calibration activity that happens every six months includes a portion of nighttime time data acquired in day mode and then a portion of day time data acquired in night mode. As a result, these periods include night time granules that contain a "day" flag during this calibration activity for granules over Africa. Additionally, granules appear missing in the global browse during the daytime time to compensate for the additional data in the buffer. The global browse image below shows an example of the impact from this calibration activity. This rolling note will document these semi annual occurrences.<br><br><br><br><b><center>************************************************ <p style="color:blue">Data users can access a complete entire mission list of all MODIS TERRA and AQUA Nighttime Day Mode Events, which includes this routine calibration activity<A href="https://mcst.gsfc.nasa.gov/modis-events-categories/routine-calibrations/nighttime-day-mode?event_date%5Bvalue%5D%5Byear%5D=2000&modis_mission=61"> HERE</A> </p> ************************************************</b></center><br><br><br><br><br><br> |
| PM_MODLWM_19290 | 2019-10-17 | 2019-10-18 | Note | Incorrect Land Water Mask classification in costal regions The MODIS Land Water Mask (LWM) that is used for the production of all MODIS Collection 6 (C6) and Collection 61 (C61) land products, is a set of static files that were produced as part of Collection 5 and delivered, prior to C6 re-processing. This LWM is known to flag some of the land adjoining coastal areas incorrectly as water. One such example over Manhattan in New York City, is shown below in the red box. The LWM is propagated through all L2 and L3 downstream products, so most land products will be impacted by this issue. A few examples across the different impacted land products have also been included below.<br><br><br>The most recent version of LWM that is being produced as annual MOD44W products in C6, which corrects this error and will be used in future Collection 7 of MODIS land re-processing.<br><br> |
| PM_MOD11_19281 | 2019-10-08 | 2019-10-08 | Note | C6 re-processing of L2/L3 LST products, September 2019 MODAPS re-processed LST products for a period between September 8th (2019.251) and September 23rd (2019.266) 2019. This included both MODIS Terra and Aqua LST products from Collection 6, including MOD11_L2/MYD11_L2, MOD11A1/MYD11A1, and MOD11B1/MYD11B1. The re-processing was caused by an error related to the science data production. During this re-processing period the science code was not changed and the quality of the LST products will not be impacted in any way. Users who have previously downloaded these products before this re-processing occurred can continue to use them without the need to procure data from this time period again.<br><br><br><br> |
| PM_MOD_19242 | 2019-08-30 | 2019-09-03 | Note | Data loss Due to PWA anomaly 2019.242 On August 30th, 2019 (2019.242) the Terra spacecraft experienced a Printed Wire Assembly (PWA) failure in the MODIS instrument between 06:14:40 and 18:48:00 on 2019.242. Because a component of the buffer that stores data had broken, there was continuous data loss throughout the day as MODIS was continuously attempting to write data to the malfunctioned PWA. A fix was implemented and this process required temporarily disabling science recording of all buffers, which also resulted in a small amount of data loss. This anomaly has since been resolved and the MODIS instrument has returned to normal operating status. The impacted times are listed below, users should be aware that these data are not recoverable.<br><br> MODIS Data Loss 2019-242<br>06:16:40 through 06:30:33 Duration: 00:13:53<br> 08:13:33 through 08:18:08 Duration: 00:04:35<br> 10:01:07 through 10:05:42 Duration: 00:04:35<br> 11:48:42 through 11:53:16 Duration: 00:04:34<br> 13:36:16 through 13:40:50 Duration: 00:04:34<br> 15:23:51 through 15:28:24 Duration: 00:04:33<br> 17:11:24 through 17:23:07 Duration: 00:11:43<br> 18:41:14 through 18:47:59 Duration: 00:06:45<br> <br> |
| PM_MOD_19179 | 2019-07-03 | 2019-07-03 | Note | Data loss Due to PWA failure 2019.179 On June 28th, 2019 (2019.179) the Terra spacecraft experienced a Printed Wire Assembly (PWA) failure within the MISR instrument. After further investigation, it was determined that Super Sets 74 and 75 failed. To fix the anomaly, Super Sets 74 and 75 were removed from MISR and this process required temporarily disabling science recording of all buffers. This resulted in a small amount of data loss within the TERRA MODIS instrument between 179/21:08:03 - 179/21:15:09. This data is not recoverable. The data loss occurred during the end of a daytime orbit over the South Pacific Ocean and the Antarctic. Due to this data loss L1B granules 21:05, 21:10, and 21:15 are not produced for this period. The global browse image below shows the data loss over this region. <br><br> |
| PM_MOD_19135 | 2019-05-21 | 2019-05-21 | Closed | Terra MODIS SRCA Xtalk test impact 2018.281 On May 15th 2019 (2019.135), the MODIS Characterization Support Team (MCST) and MODIS Instrument Operations Team (IOT) performed a calibration test on the Terra MODIS instrument using the SRCA to evaluate the crosstalk between bands. The test was designed to borrow frames from the solar diffuser sector to the SRCA sector. However, an unforeseen issue was encountered during the test, after which, the test was aborted. The impact of this event is observed in the TOA L1B data for granules 14:45 through 17:30 (inclusive) on DOY 2019.135. During the attempted calibration effort the TOA L1B data and downstream products were directly impacted during both daytime and nighttime orbits as impacted granules contain a striped artifact, which runs the length of the granules along the right outer edge.<br><br>Daytime granules:<br>Granules from Daytime orbits report anomalous L1B TOA reflectance and thermal values within this artifact across all bands. The associated L1B TOA reflectance uncertainty index for the daytime granules report a mixed range of values between 4 and 7, and a value of 0 in the emissive uncertainty index. Below, the images show example granules of L1B TOA reflectance and emissive bands with their associated uncertainty index values. The L1B did not flag these areas as anomalous either through _FillValue or uncertainly index so all downstream daytime products will be impacted. |
| PM_MOD_22196 | 2022-08-15 | 2022-08-15 | Note | Data loss due to a contact error 2022.196 (07.15.22) On July 15th, 2022 (2022.196) a contact error occurred, which resulted in a nonrecoverable data loss for Terra MODIS. The unrecoverable data loss impacts time 2022.196 (14:17:53 - 14:18:06), which occurred during a night time orbit over the Antarctic. The L1B emissive bands and geolocation were reviewed and granule 14:15 was verified to contain this data gap. Processing has been closed and the data is not recoverable. The two images below shows the L1B emissive band and geolocation information for granule 14:15.<br><br> |
| PM_MOD_19124 | 2019-05-08 | 2019-05-08 | Note | Data loss Due to Contact Error 2019.124 On May 4th, 2019 (2019.124) the Terra MODIS instrument experienced a contact error, which resulted in a data gap in granule 11:05. Data is recoverable but has not been recovered. The images below shows the Terra MODIS L1B geolocation and MOD021KM reflectance for granule 11:05, 2019.124. The data gap occurred during a daytime orbit over the South Atlantic Ocean. This note will be updated if the gap in the data is recovered.<br><br> |
| PM_MOD17_19088 | 2019-03-29 | 2019-03-29 | Note | MXD17A2H data discrepancies A few production periods of the MOD17A2H and MYD17A2H from the operational C6 processing have been identified as containing incomplete or corrupt data. These 8-day periods are listed below for each sensor. LDOPE is currently working with production to investigate, fix, and regenerate these periods. A global browse image below shows one example of the data discrepancy observed in the 17A2 archive. This note will be updated as more information becomes available.<br><br>MOD17A2H:<br>2018153<br>2017233<br>2016353<br>2016361<br>2001177<br><br>MYD17A2H:<br>2018161<br>2018153<br>2018145<br>2017217<br>2015345</A><br><br><br><br><br><br> |
| PM_MOD02_19066 | 2019-03-07 | 2019-03-07 | Pending | Dead and Noisy Detectors Band 5 The TERRA MODIS C6 L1B product MOD02HKM contains striping from detector 4 in band 5. The detector is flagged as in-operable in the L1B QA LUT. In the L1B product these flagged detector scanlines contain fill values indicating the detector status, unlike the product from earlier collection reprocessing, where these detectors are replaced by adjacent detector values. The example below shows images of band 5 from the L1B MOD02HKM granule, where detector 4 can be seen as the white stripe running horizontal across the granule. <br><br>Additionally, detectors 3 and 5 (product order) have been exhibiting out of family behavior in terms of the instrument gain derived from solar diffuser calibrations. The two detectors appear to have an influence by the increasingly irregular behavior of band 5 detector 17 (i.e. 4 in product order) which has had out-of-family behavior since early in the mission and is currently labeled in-operable in the QA LUT. MCST will continue to monitor the performance and evaluate correction methodologies and the QA flags for the two detectors 16 and 18 will be labeled as out-of-family for the next C6 and C6.1 LUT update. The small image below shows biased values in detector 3 and 5 surrounding the white stripe caused by the inoperable detector 4. |
| PM_MOD17_19056 | 2019-02-25 | 2019-02-25 | Note | Annual GPP/NPP discontinued Annual MOD17A3H/MYD17A3H and MOD16A3/MYD16A3 (version 5) from the operational C6 processing has been discontinued because of irregular retrieval issues and users are advised not to use this data, even if they had downloaded this data previously from LP-DAAC. Instead, MODAPS will introduce in a couple months an improved gap-filled year end M*D16A3GF and M*D17A3GF products (version 6) as part of collection 6 products. For immediate use, the users are advised to use the Annual MOD16/MOD17 products from NTSG: found <A href="https://www.ntsg.umt.edu/project/modis/">HERE</A>. For more information users can reference <A href="https://lpdaac.usgs.gov/note_users_use_modis_gppnpp_mod17_datasets"> the note posted on the improved MOD17 product.</A><br><br> |
| PM_MOD_19035 | 2019-02-07 | 2019-02-07 | Note | Data loss Due to Contact Error 2019.035 On February 4th, 2019 (2019.035) the Terra MODIS instrument experienced a contact error, which resulted in a data gap in granules 21:00 and 21:10. Data is recoverable but has not been recovered. The images below shows the Terra MODIS L1B geolocation and MOD021KM reflectance for granules 21:00 and 21:10 2019.035. The data gap occurred during a daytime orbit over the Pacific Ocean and Antarctica. This note will be updated if the gap in the data is recovered.<br><br> |
| PM_MOD02_18345 | 2018-12-11 | 2018-12-11 | Note | Known Issues affecting Terra MODIS Instrument performance MCST (MODIS Calibration Support Team) tracks the prominent performance factors that complicate achieving optimum performance of the MODIS instrument, which are listed below. For a description of these effects, the projected impact on the L1B and L2 science, the instrument characteristic causing the effect, and the current mitigation strategy, access the following <A href="https://mcst.gsfc.nasa.gov/calibration/known-issues">MCST website LINK</A><br><br>TERRA known Issues:<br>-Non - functional or noisy detectors<br>-Incomplete knowledge of sensor response across the scan (TEB)<br>-Incomplete knowledge of sensor response across the scan (RSB)<br>-Optical cross - talk (Band 31 into Bands 32 - 36)<br>-Electronic cross - talk (Bands 5 - 7, 20 - 26)<br>-Thermal leak (Bands 5, 6, 7 and 26)<br>-Non - uniform digital count (DN) bin - fill factors (bin - width)<br>-Channel to channel non - uniform response functions within a band<br>-Band 27 anomalous band width, anomalous gain<br>-Degradation in RSB (Bands 1 - 19, plus 26)<br>-Incomplete calibration for Band 21<br>-High Saturation Brightness Temperature in the Sea Surface Temperature (SST) Bands (11<br>-and 12 micrometers/Bands 31 and 32)<br>-Mirror rotation correlated noise<br>-Band 21(detector 1, product order) and Band 24(detector 1, product order) striping<br>-Mis - registration of 250 and 500 meter resolution bands to the 1000 meter resolution bands<br>-Mirror-side differences<br>-Spacecraft effects: removed data<br>-Polarization effects<br><br> |
| PM_MOD_18315 | 2018-11-15 | 2018-11-15 | Note | Terra PV ECAL data Loss 2018.315 (11.11.18) On November 11th, 2018 (2018.315) a Photovoltaic bands electronics calibration event (PV ECAL) occurred, which impacted the Terra MODIS instrument data. between 2018/315 21:47:46-21:50:17. During this period it was found that granules 21:45 and 21:50 both contain a data gap in the emissive bands. This occurred during a night time orbit over Greenland. The geolocation was reviewed for both granules and no impact was observed. However, granule 21:45 was found to contain corrupt, bad quality emissive values, which could potentially be used as good. The example images below show the L1B data emissive band and associated geolocation information. The data is not recoverable.<br><br> |
| PM_MOD_18302 | 2018-11-01 | 2018-11-01 | Note | Terra Data Loss 2018.302 (10.29.18) On October 29th, 2018 (2018.302) the Terra MODIS instrument experienced a contact error that resulted in a small data loss from 302/16:25:41 - 302/16:25:44. The data loss occurred during a daytime orbit over the South Pacific Ocean. The images below show the reflectance and geolocation information for granule 1625, where the 3 second data loss occurred. The data is not recoverable.<br><br> |
| PM_MOD21_18283 | 2018-10-10 | 2018-11-05 | Note | cross-talk in b29 impacts years post 2005 in C6 The C6 MOD21 suite of products (MOD21 L2, MOD21A1D/N and MOD21A2) will not be available for MODIS TERRA beyond the year 2005. This is due to increased impact of cross-talk in the Terra Band 29 after year 2005. Hence, in C6 for mission period after 2005 only MYD21 suite of products from MODIS Aqua will be available. However, once the new Collection C61 land products become operational, both the MOD21 and MYD21 suite of products will be available for both MODIS TERRA and AQUA respectively, as the cross-talk issue has been corrected in the C61 L1B. The Terra MOD21 data from the beginning of the mission till 2005 has been released to public with provisional maturity status as these products could also be negatively impacted by the optical crosstalk present in IR bands, though may not be as bad as all years after 2005.<br><br> |
| PM_MOD_18281 | 2018-10-09 | 2018-10-19 | Note | High Gain Antenna anomaly 2018.281 (October 8 around 1244 GMT), the Terra High Gain Antenna experienced an anomaly. Since the anomaly, until the HGA was returned at nominal operation just before 0000 GMT on 10/09 communications with Terra have been through the omni antenna. During this period Terra was in science mode collecting data, but with the band limited omni antenna communications through the ground stations some science data was being lost in between some of the ground station contacts. Since the recovery of the HGS antenna, Terra has returned to routine science data downlink through TDRS via the HGA. This issue is currently under investigation.<br><br><br>****Updated NOTE****<br>The Terra Data Loss #1022 for 281.2018 has been submitted and all missing data are not recoverable.<br><br>The overall impacted period was 2018/281 12:05:04 through 281/22:51:48. Missing data periods that are not recoverable within this rage include:<br>12:15 through 13:15<br>13:55 through 14:30<br>21:10 through 22:05<br>22:50 through 23:35<br><br> Additional, a small geolocation data loss was identified in granule 22:20. <br><br>The first image below shows the overall missing data in the global browse image for 2018.281. |
| AS_MOD_22144 | 2022-05-24 | 2022-05-24 | Note | Terra Data Outages Associated With MODIS Water Reservoir Product Gaps The dates listed below are associated with TERRA outages in which MODIS water reservoir products (MOD28) were not generated due to an issue with overlapping reservoir data. Roughly 1 in 5 reservoirs overlap two or more tiles. If any of that data is missing due to an outage or otherwise, the metrics would be underestimated. As a result, the PGE does not run for that period and data is not produced. The listed dates cannot and will not be re-generated in the future for this this collection, however a future collection may use a different PGE where this scenario is accounted for.<br><br><br><br><b><center>******************** <p style="color:blue">MAIAC Outage Events Concerning AQUA Products Can Be Found <a href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=134">HERE</a></p> ********************</b></center><br><br>MOD28C2 - 06/18/2001 (169)<br>MOD28C2 - 06/26/2001 (177)<br>MOD28C2 - 02/18/2016 (049) <br><br> |
| PM_MOD_18270a | 2018-10-09 | 2018-10-09 | Note | Terra Data Loss #1021 for 2018.270 On September 27th, 2018 (2018.270) the Terra MODIS instrument experienced a contact error that resulted in a small data loss from 270/19:36:16 through 270/19:36:23. The data loss occurred during a daytime orbit over the Southern Pacific Ocean. The images below show the reflectance and geolocation of granule 1935, where the data loss occurred. The data is recoverable but has not been recovered.<br><br> |
| PM_MOD_18270 | 2018-09-28 | 2018-10-09 | Note | Terra MODIS standby mode 2018.270 Terra MODIS was put in standby mode, following expiration of the daily stored command load at 20:00 UTC on September 27, 2018. There will be no science data acquired until further notice. The cause of the incident is still being investigated and work is in progress to recover the instrument.<br><br>****NOTE**** The MODIS instrument has been recovered. As a result of this event, granules 2018.270 20:55 through 2018.271 01:45 inclusive, were found to be impacted with bad quality data. Additionally, granules from 2018/270 20:00 through 20:55 and 2018/271 01:45-01:50 were also found to be corrupt and both periods of impacted data have been removed from C6 processing.<br><br> |
| PM_MOD21_18255 | 2018-09-12 | 2018-09-21 | Closed | High LST values due to striping in emissive bands The operational C6 MxD21 products show high LST values over pixels where the input L1B emissive bands 31/32 show striping. LST is retrieved despite the MODLAND mandatory QA bits (bits 0-1), flagging these pixels as "Pixel not produced". Ideally, no LST retrieval should have been attempted over such pixels and a FillValue should have been assigned to these pixels. The images below show the C6 MOD21 high LST values, the QA flags, and the associated striping in the L1B emissive band 31.<br><br> |
| PM_MOD_18209 | 2018-07-31 | 2018-07-31 | Note | Data loss due to contact error 2018.209 On July 28th (2018.209) the Terra MODIS instrument experienced a contact error, which resulted in a data gap between 13:36:06 and 13:43:29. The data is not recoverable for this period. The images below shows the Terra MODIS L1B geolocation and MOD021KM reflectance granule 13:35 for 2018.208. The data gap occurred during a daytime orbit off the coast of Argentina. |
| PM_MOD_18135 | 2018-05-24 | 2018-05-30 | Note | Terra Data Loss 2018.0135 (05.15.18) On DOY 2018.135 (05.15.18) Terra MODIS experienced a data loss between 135/01:45:40 to 135/04:47:485 due to a contact error. This was observed in the forward processing as a data gap during a daytime time orbit over southeast Asia and the Indian Ocean. The data loss is recoverable, however granules 04:30 through 04:50 inclusive, continue to be unrecovered from this data loss. This note will be updated if the data is recovered. The image below shows the global browse image for TERRA L1B reflectance where the data loss is observed over Southeast Asia and the Indian Ocean. |
| PM_MOD02_18079a | 2018-03-23 | 2018-09-26 | Note | Dead Detectors Band 7 Terra MODIS C6 L1B product MOD02HKM contain striping from detector 14 in band 7. These are flagged as in-operable in the L1B QA LUT. In the L1B product these flagged detector scanlines contain fill values indicating the detector status, unlike the product from earlier collection reprocessing, where these detectors are replaced by adjacent detector values. The following example shows images of band 7 from the L1B MOD02HKM granule. <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=84">Downstream impacts in MOD09 surface reflectance products are documented here</A>.<br><br><br><br><br><br> |
| PM_MOD02_18079 | 2018-03-22 | 2019-02-12 | Note | Dead Detectors Band 6 Terra MODIS C6 L1B product MOD02HKM contain striping from detectors 3 and 7 in band 6. They are flagged as dead or in-operable in the L1B QA LUT from the start of mission up to DOY 2000.305. In the L1B product these detector scanlines contain fill values indicating the detector status, unlike the product from earlier collection reprocessing where these detectors are replaced by adjacent detector values. These stripes are propagated to downstream product like surface reflectance and albedo. The example image below shows band 6 from the L1B MOD02HKM granule. <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=84">Downstream impacts in MOD09 surface reflectance products are documented here</A>.<br><br>Users should be aware that the band 6 detectors 3 and 7 were classed as Non-Functional Detectors (QA bit 1) prior to DOY 2000.305 (October 31, 2000). From the start of mission up to DOY 2000.305, the A-side electronics of the TERRA MODIS instrument was in use. On DOY 2000.304 the instrument was switched to the B-side electronics, at which time these detectors were treated as functional. Prior to the B-side switch, the L1B and downstream products are heavily impacted by striping form the dead detectors.<A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=90">Additional downstream impacts in MOD10 snow product are documented here.</A> <br><br><br> For a complete list of dead detectors for each band in current C6 processing, please refer <A href="https://landweb.modaps.eosdis.nasa.gov/data/userguide/Terra_C6_DQF_Table_072616_0.xlsx">to this table from MCST.</A><br><br><br> |
| PM_MOD16_18074 | 2018-03-15 | 2018-03-15 | Pending | Using the QA dataset in the Terra and Aqua ET product The pixel level QA dataset ET_QC_500m is a copy of the pixel level QA of in the input 8-day composite LAI-FPAR product (MxD15A2) and does not reflect the quality of the retrieved Evapotranspiration. The current operational C6 version of the process does not generate pixel level science quality information. Users are advised to exercise caution while using the product in their application. Because of this user may also find Pixels with fill values being flagged as qualified retrievals. Also in some cases user may find retrievals with value attributed to barren land where the underlying land cover could be a vegetated area like forest.<br><br> |
| PM_MOD_18039 | 2018-02-12 | 2018-02-12 | Note | Terra Data Loss 2018.039 (02.08.18) On DOY 2018.039 (02.08.18) Terra MODIS experienced a data loss between 039/08:44:43 and 039/09:55:55 due to a contact error. This was observed in the forward processing as a data gap during a daytime time orbit over southern Africa. Granules 09:30 through 09:45, inclusive, were missing form this data loss. The image below shows the global browse image for TERRA surface reflectance where the data loss is observed over southern Africa. |
| PM_MOD21_17307 | 2017-11-03 | 2018-11-27 | Closed | Discrepancy in MxD21 suite of LST products The C6 MxD21 products were found to contain incorrect LST values. Emissivities that are too low over many regions and LST values that are too high are also consistently observed globally in the most recent version of the C6 MOD21 L2 data. This issue has been traced to a potential coding error in interpolation of the WVS coefficients. The issue impacts the L2 data and downstream L3 LST daily and 8-day composite products (MxD21A1/ MxD21A2).Users should be aware that the current suite of products has been found to be unusable for science and validation purposes.<br><br> Below is a comparison of a C6 processed MOD21 LST granule compared to MOD11 LST. The L2 MOD21 granule over western Africa shows a much larger temperature range than observed in MOD11. The third image shows the absolute difference image (MOD21 - MOD11) the specific differences can be observed.<br><br><br><br>NOTE: This issue has been addressed in the current operational version of the C6 using the revised suite of PGEs with software fix to address this and several other minor known issues in the product. |
| AS_MOD_22111 | 2022-04-21 | 2022-05-19 | Closed | MODIS TERRA Data Gap 2022.109 (04/19/22) Terra MODIS is missing all data for 04.19.2022 (2022109) between 19:02:17z - 19:04:51z. As a result, granule 109/19:00z shows a gap. The cause of the data gap as well as whether this data can be recovered is currently unknown.<br><br><br><br><b><center>******************** <p style="color:red">Terra Data Gap: UPDATE 05.19.22</p> ********************</b></center><br><br>During the TDRSS contact with TDW (20:15:22 - 20:33:22z), there was no S-Band or K-Band being received at AOS. The OCE contacted White Sands and was informed of an anomaly with TDW. It also affected the following TDW contact at 20:40:00z. On the next TDRSS contact with TDS (21:22:00 - 21:40z), the OCE executed replays on all the buffers to recover as much data as possible that was affected by the TDW anomaly. On the upcoming TDW contact at 21:57:56z, telemetry was received, and White Sands stated that TDW should be working nominally. The Data Continuity Report showed data gaps in the MODIS buffer. A ground track was generated, and the DB community was notified to see if the data could be recovered. However, the ground track showed Terra at a location above the South Pacific, and there were no DB sites in the vicinity to recover the lost data. Thus, the data is not recoverable. |
| PM_MOD21_17304 | 2017-10-31 | 2018-09-12 | Closed | Higher than expected temperatures over high humidity regions The MxD21 products were found to contain higher than normal LST values for areas with high humidity conditions, a result of lower than expected emissivities in band 31 retrieved for these area. This has been traced to a potential coding error in interpolation of the WVS coefficients. The issue might have also propagated to the downstream L3 LST daily and 8-day composite products (MxD21A1/ MxD21A2). <br><br>Note: Operational processing and distribution of the product has been discontinued. Products will be re-reprocessed in C6 using revised suite of PGEs with software fix to address this and several other minor known issues in the product.<br><br> |
| PM_MOD03_17282 | 2017-10-18 | 2017-10-18 | Note | Geolocation gap during maneuver period 2017.282 (10.09.17) The Terra MOD03 granule 2017-282 16:20 contains a few rows and columns of fill values instead of valid geolocation data. Fill value rows in the geolocation data are also observed in the corresponding L1 MOD021KM granule 16:20. The images below show the geolocation stripe in the latitude layer of MOD03 granule 16:20 and a larger data gap in the L1B granule. This data loss is a result of a known maneuver period. Additionally, the data gap occurs in granule 16:20 during a night time orbit over Asia. However, the day/night flag incorrectly reports 'both'.<br><br> |
| PM_MOD_17262 | 2017-09-21 | 2017-09-21 | Note | Terra Data Gap 2017.262 (09.19.17) On DOY 2017.262 (09.19.17) Terra MODIS experienced a data outage due to a contact error. This was observed in the forward processing as a data gaps over Northern Canada, with a loss of geolocation information for granules 22:00 and 22:05. The images below show the geolocation information and associated L1B reflectance for granule 22:05, where the data loss can be observed. This data is recoverable but has not been recovered.<br><br> |
| PM_MOD_17355 | 2017-09-21 | 2017-09-21 | Note | Terra Data Loss 2017.355 (12.21.17) On DOY 2017.355 (12.21.17) Terra MODIS experienced a data loss due to a Printed Wire Assembly (PWA) failure. This was observed in the forward processing as a data gap during a night time orbit over South Atlantic Ocean, off the coast of Namibia. The data recovery has been completed and the loss of science data is 2017/355 22:36:04z to 22:43:11z.<br><br> |
| PM_MOD13_17242 | 2017-08-30 | 2017-10-02 | Note | Improvement to VI in forward processing starting data day 2017241 A revised version of the VI PGEs, PGE25(6.0.34)/PGE35(6.0.23), with changes in the science processing software to address following issues were put in the C6 forward processing on data day 2017241.<br>- Missing large swath of data (GAPS) in the 250m & 500m records especially in the last cycles of each year (due to staging errors and a Code bug that did not capture the staging issue)<br>- VI usefulness bit reset<br>- High spikes or No Data in the 250m record<br>The new software also includes code changes to improve product quality by <br>- logic for composited to bin optimize NDVI under 30VZA for good quality data.<br>- Backup EVI equation updated to use the EVI2.<br><br>The VI suite of products in the forward processing from data day 2017241 onwards could have differences compared to the product from the prior period of the mission. The difference would be in the form of<br>- 250m fill values minimized<br>- Most spikes are removed, though some remain in the data due to the use of pre-composited 8day input files <br>- Change in near about 10 to 20 percent of the global retrievals <br>- Overall a slight increase in NDVI and EVI values, with relative difference being less than 1%<br>- Decrease in percent clouds<br>- Compositing day remains for the most part the same<br><br> |
| PM_MOD_17227 | 2017-08-15 | 2017-08-15 | Note | Data loss from Terra Deep Space Maneuver on 2017-08-05 (2017.217) On 08.05.17 (2017.217) a deep space calibration maneuver was performed for Terra, starting at 23:15:46 GMT and ending at 23:51:40. Because of this the instrument was put in Day Collection mode during this time for all bands, to collect data for calibration. Hence some of the night time granules falling within this time were flipped to day time mode while some other day time granules, outside this range, were flipped to night time, to prevent data storage overflow for the onboard data recorders. Some of the other granules, falling within this time were also found to have geolocation issues. As a result all granules falling between the time 23:00 GMT and 23:55 GMT were removed from processing for this day, for L1B and all downstream L2 products. <br><br> |
| PM_MOD10_17220 | 2017-08-08 | 2019-02-11 | Note | Dead Detector band 6, early mission impact The Terra MODIS C6 snow products contain striping artifact. This has been traced to the upstream L1B product, MOD02HKM, <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=75">due to the presence of two dead detectors, detectors 3 and 7 in Band 6 of Terra MODIS.</A> The following example shows images of full resolution (in first row) and spatial subset (in second row) of L2 snow product (image on the left) and the input L1B product (MOD02HKM) from Terra day 2000115. The striping in images of snow product are in the same line as the striping in the L1B product.</A><br><br><br> |
| PM_MOD_17212 | 2017-08-02 | 2017-08-02 | Note | Terra Science Formatter Equipment(SFE)Anomaly 2017-07-31 (2017.212) On 07.31.17 (2017.212) the Terra instrument experienced a data corruption stemming from an SFE Anomaly. The data loss occurred between 03:34:37z and 03:40:12z, impacting L1B 03:30, 03:35, 03:40 granules and downstream data products. This data loss is not recoverable. The images below show the geolocation information and associated L1B reflectance for granule 03:30, where the data loss can be observed during a night time orbit over Chile.<br><br> |
| PM_MOD_17185 | 2017-07-10 | 2017-07-10 | Note | Terra Data Gap 2017.185 (07.04.17) On DOY 2017.185 (07.04.17) Terra MODIS experienced a data outage due to a contact error. This was observed in the forward processing as a data gap over the Northern coast of Norway, with a loss of geolocation information for granule 19:10. The images below show the geolocation information and associated L1B reflectance for granule 19:10, where the data loss can be observed. This data is recoverable but has not been recovered.<br><br> |
| PM_MOD21_17181 | 2017-06-30 | 2017-07-05 | Note | MxD21 LST SDS name variation The M[O|Y]D21 L2 and M[O|Y]D21D/N L3 daily products contains incorrect values associated with the units, data type, and valid range reported in the SDS 'PWV'. These inconsistencies have been later corrected in the forward processing.<br><br>Example of incorrect values:<br>units: "n/a"<br>data type: "INT16"<br>valid_range: "-32767.0,32767.0"<br><br>Correction implemented in the forward processing:<br>units: "cm"<br>data type: "UINT16" <br>valid_range: "0.0,65535.0"<br><br>In Terra the inconsistencies are observed from the start of the mission until 2006.240. And in Aqua they are observed from the start of the mission until 2014.057. Users should be aware that these issues have been addressed in the forward processing for Terra and Aqua, and users are advised to reference the latest userguide for the details associated with each attributes correct value. <br><br> |
| PM_MOD_22074 | 2022-03-15 | 2022-04-15 | Closed | MODIS TERRA SEU Reset 2022.074 (03/15/22) Terra MODIS encountered a SEU Command Processor and Format Processor reset today 03.15.22 (2022.074) at around 08:54z. As a result, MODIS entered standby mode. Though the data acquisition is going on, with some interruptions between 08:45z - 09:40z, the science quality will be degraded as the onboard calibrators (blackbody) is turned off and the onboard tables were reverted back to their at-launch values.<br><br>As a CP reset was encountered, subsequent patches need to be uploaded to the S/C after MODIS is recovered from the Standby mode. As a result of this, the recovery plan was divided into two parts, whereby in the first part, MODIS is to be transitioned from the standby to science mode and critical patches uploaded. The second part involves uploading more patches and gain tables to return the same configuration as before the anomaly. MCST and FOT are working to perform the recovery process. Recovery is expected to be in two phases:<br>- Bring the instrument back to science mode [074/22:21:28z]<br>- Upload revised tables to return to the pre-anomaly configuration [074/22:23:38z].<br><br>MODIS continues to operate normally with the FPA and instrument temperatures showing nominal values. While MCST continues to perform a detailed evaluation of the radiometric performance of the instrument since the anomaly, the data since the anomaly is expected to be of a degraded science quality. In particular, band 5 gains (reset to at-launch value due to this anomaly) is expected to show about 20-30% difference relative to pre-anomaly levels. We expect these to return to pre-anomaly levels once the entire recovery process is complete. We will keep you posted on the instrument recovery status and data anomaly. Further details may be available in <a href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=246">the NRT note</a>.<br><br><br><br><b><center>******************** <p style="color:red">SEU Reset: UPDATE 03.15.22</p> ********************</b></center><br><br>The first part of the recovery process was completed this evening (03.15.2022) and MODIS successfully transitioned to science mode. The second part of the recovery process is to be reviewed with ART on 03.16 and subsequent recovery is planned thereafter.<br><br><br><br><b><center>******************** <p style="color:red">SEU Reset: UPDATE 03.17.22</p> ********************</b></center><br><br>The MODIS IOT performed the second part of the commanding to upload additional patches and gain tables to successfully return the MODIS instrument to the same configuration as before the anomaly. All the commanding was successfully performed. Band 5 gains have returned to pre-anomaly levels, however, we expect degraded science data quality through about 076/02:20, when the SCI_ABNORM_FLAG was set back. A more detailed timeline of the outages is being compiled. Over the next few days, radiometric performance will continue to be evaluated and any updates will be reported.<br><br><br><br><b><center>******************** <p style="color:red">SEU Reset: UPDATE 03.29.22</p> ********************</b></center><br><br>MODAPS will re-process all affected Terra L1B, L2, and L3 dailies and 8-day products for C6 (2022074 - 2022076) and C61 (2022074 - 2022084). This has become necessary in light of the post-event assessment performed by the MODIS Calibration Team (MCST) which suggested the following after-effects:<br>1) Minor gain changes that were noticed in the RSB bands, with band 5 showing significant gain change.<br>2) Amongst the TEB bands, band 21 is showing slightly higher noise levels.<br>3) Changes noticed in mirror side differences.<br><br>For more details, users may refer to the <a href="https://landweb.modaps.eosdis.nasa.gov/data/userguide/Terra_CP_FP_Reset_MCST_PostAssessment.pdf">MCST findings.</a><br><br><br><br><b><center>******************** <p style="color:red">SEU Reset: UPDATE 04.15.22</p> ********************</b></center><br><br>All affected Terra products, both dailies and n-days, have been re-processed for both C6 and C61. This issue is now considered resolved.<br><br> |
| PM_MOD21_17179 | 2017-06-28 | 2017-06-28 | Note | QA layer stripes due to a dead detector MOD21, the Terra LST QA layers from day 2006241 and onwards contains systematic stripes due to a <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=108">dead detector</A> in band 29 of Terra MODIS. To cosmetically account for the impacts of the dead detector values during qualitative analysis and plotting, the nearest neighbor averaging was calculated in the LST product. This adjustment visually removed the stripes caused by the dead detector from the LST product layer. However, the QA flags of bits 0-1 and bits 2-3 continue to report a value of "11" for pixels impacted by the dead detector. Users should be aware that pixels containing these flags should not be used for analysis. QA Bits 0-1 = 11 "Pixel not produced due to reasons other than cloud (e.g. ocean pixel, poorly calibrated input radiance, TES algorithm divergence flag)" is the most relevant flag as dead detector pixels are not produced because the TES algorithm requires all three TIR bands to be good.<br><br> The image below shows the MOD21 LST comparison of day 2006.241.1530. The left image is MOD21LST, the middle image is the QA flag for bit 0-1, and the right image is the L1B b29, which shows the dead detector stripes. |
| PM_MOD_17162 | 2017-06-16 | 2017-06-19 | Note | Data loss due to safe configuration event on 2017.162 (06.11.17) On DOY 2017.162 the Terra MODIS instrument experienced a data loss as an anomaly triggered the spacecraft to transition into a safe configuration. TDS was unable to support Terra during this time as data management required manual PBs, Flexes, and replays, generally taking up all available contact time. MODIS data loss occurred due to this event with the times impacted listed below. Data is recoverable but has not been recovered. The images below show the geolocation information and associated L1B emissive band 33 for granule 09:00, where the data loss can be observed. <br><br><br>2017/162 05:59:06 - 05:59:16 (DAY mode) 15,415 CADU <br>2017/162 05:59:56 - 06:00:16 (DAY mode) 28,628 CADU<br>2017/162 09:01:39 - 09:02:07 (NIGHT mode) 12,501 CADU <br>2017/162 09:04:05 - 09:05:22 (NIGHT mode) 34,213 CADU.<br><br> |
| PM_MOD16_17166 | 2017-06-15 | 2017-06-15 | Note | Gaps cause underestimated values in MxD16 products The operational C6 NASA MOD16 and MYD16 A2 and A3 products generated at MODAPS, and available to public from LP-DAAC and LAADS contain large areas flagged as barren containing fill value at these pixels. The area other than real desert or arid land flagged as barren corresponds to no retrieval because of persistent cloud cover. However the same product generated and distributed by the Science Computing Facility at the NTSG, University of Montana contain valid retrievals for these pixels. The SCF version of the product was generated at the end of the year using gap filled LAI/FPAR product as input. The example below, shows the global browse image of the Terra MOD16A2 product generated at NTSG at the top, followed by global browse images of the Terra and Aqua MOD16A2 product generated through operational processing at MODAPS. While the top image shows retrieval for all area except of desert and semi-arid area, the middle and bottom images show bronze color over the high latitudes of Asia and North America and also in the tropical regions of South America and central Africa. <br><br> |
| PM_MOD21_17164 | 2017-06-13 | 2017-06-13 | Note | Incorrect metadata for PWV data range and units The SDS attribute in the MxD21 data is incorrect, there is a mistake in the product metadata for PWV data range and units. In the MxD21 swath for the water vapor SDS parameters the metadata reports units as n/a with a valid range of -32767.0 to 32767, and this is incorrect. The correct units are cm and the valid range is 0 to 65535. Users should be aware that the user guide reports the correct metadata units and range. Due to this issue, data produced prior to June 2017 in the archive may report incorrect metadata. The source code will be updated and the corrected metadata units and range for PWV will be reflected in the forward processing. <br><br> |
| PM_MOD21_17159 | 2017-06-08 | 2017-06-08 | Pending | Striping in Terra LST MOD21 from dead detector in Band 29 MOD21, the Terra LST product from day 2006241 and onwards contains systematic stripes of very large LST values. This has been traced to a dead detector in band 29 of Terra MODIS which is not being handled correctly by the science processing algorithm. All data days impacted by this error in processing will be reprocessed using the revised version of the algorithm with software patch to handle the dead detectors. LST from processing of Aqua MODIS does not contain any such anomaly. <br><br> |
| PM_MOD21_17159a | 2017-06-08 | 2017-06-08 | Note | Difference between MERRA based and NCEP based LST Processing of operational C6 LST product MOD21 and MYD21 at MODAPS (and the product available to public from LPDAAC and LAADS) is expected to lag by 1-2 months as the MERRA2 ancillary input used in the processing of the product is available 1-2 month later. However for near real time use the same product is generated using NCEP as ancillary by the MODAPS-NRT processing system and is distributed to public by the LAADS-NRT rolling archive which will only archive the data for the latest two months of the mission. User should expect difference in the LST at pixel level from these two versions of the product because of difference in the accuracy of the daily atmosphere profiles and the difference in resolution of these two ancillary data source. Additionally, users are recommended not to mix the two versions (NCEP-based and MERRA2-based) of LST products in their analysis because the difference in LST from these two version of products can be as large as 5-10 degrees K over some areas.<br><br> |
| PM_MOD_17154 | 2017-06-06 | 2017-06-06 | Note | Terra Data Gap due to playback error 2017.154 (06.03.17) On DOY 2017.154 (06.03.17) the Terra Spacecraft experienced a skipped EDU during a MODIS buffer playing back, which resulted in a data gap between 09:01:43z and 09:02:27z. As a result, granule 09:00 was found to contain a small data loss. This occurred during a daytime orbit over the South Atlantic Ocean. The images below show the geolocation information and associated L1B reflectance for granule 09:00, where the data loss can be observed. This data is recoverable but has not been recovered.<br><br> |
| PM_MOD_17155a | 2017-06-06 | 2017-06-06 | Note | Terra Science Formatter Equipment(SFE)Anomaly 2017-06-04 (2017.155) On 06.04.17 (2017.155) the Terra instrument experienced a data corruption stemming from an SFE Anomaly. The data loss occurred between 07:37:17z and 07:42:36z, impacting all L1B and downstream data products. This data loss is not recoverable. The images below show the geolocation information and associated L1B reflectance for granule 07:35, where the data loss can be observed over northern Russia.<br><br> |
| PM_MOD13_17131 | 2017-05-11 | 2017-10-02 | Note | Year end coding error for Nday products Some of the 250m and 500m VI tiled products (MxD13A1, MxD13Q1) may have been negatively impacted by incorrect retrievals because of a bug in the science software that makes these products (PGE25). Though in general impact from this issue on the products from any data day is insignificant or none, products generated for the 16-day period at the end of the year may have areas with no retrievals. The issue has been traced to incorrect handling of the two identical observations form the same data day that are present in the two input 8-day composite LSR products i.e. one from the last 8-day period of the current year and the other from first 8-day period of the following year. The example below shows Terra, MOD13Q1-NDVI, from day 2007353 (12/19/2007), The impacted area show as blue wide stripes over Africa and other areas corresponding to no retrievals because of this software bug.<br><br><br>NOTE: The impacted data days have been reprocessed using the revised PGEs, version PGE25(6.0.34)/PGE35(6.0.23) containing the bug fix addressing this issue and other enhancements put in the forward processing starting data day 2017241.<br><br><br> |
| PM_MOD_17114 | 2017-04-25 | 2017-05-04 | Note | Terra Science Formatter Equipment(SFE)Anomaly 2017-04-24 On 04.24.17 (2017.114) the Terra instrument experienced a data corruption stemming from an SFE Anomaly. The data loss occurred between 03:44:03z and 19:44:58z, impacting all L1B and downstream data products. The global browse image below shows the impacted data for 2017.114. This data loss is not recoverable.<br><br> |
| AS_MOD_22069 | 2022-03-10 | 2022-03-10 | Note | Terra Granule-Level Data Gap 2022.044 (02.13.22) On March 10, 2022, a data gap for Terra MODIS was reported for February 13 (2022044) between 12:00:27z and 12:00:31z corresponding to interior Antarctica. Granule 12:00z appears in both daytime and nighttime orbits, but this gap is in the daytime orbit. This data will not be recovered.<br><br> |
| PM_MOD14_17102 | 2017-04-12 | 2017-04-12 | Note | QA metadata mishandeling negative values A few tiles of the MOD14A1 8-day L3 fire product report unmapped values of 0. These are mainly ocean tiles with no land pixel, and the 0 value is a result of a possible coding error when estimating QA percent using negative values. The image below shows an example of tile h01v07, where the value of zero is observed as white.<br><br> |
| PM_MOD10_17027 | 2017-01-27 | 2017-01-27 | Pending | Incorrect begin dates reported in MXD10A2 Metadata The TERRA and AQUA MODIS C5 and C6 MOD10A2 snow products reports an incorrect begin date in the metadata. In the example below 2016-02-26, DOY 2016.057 reports a RANGEBEGINNINGDATE of 2016-02-28 in C5 and 2016-02-29 in C6. The issue has been traced to a coding error which derived the start and end date based on days for which the data was available for processing. Instead these days are supposed to be the beginning and ending of the n-day period.<br><br><br><br>MOD10A2.A2016057.h30v10.005.2016106194517.hdf<br>" OBJECT = RANGEBEGINNINGDATE\n",<br>" NUM_VAL = 1\n",<br>" VALUE = \"2016-02-28\"\n",<br>" END_OBJECT = RANGEBEGINNINGDATE\n",<br><br><br><br>MOD10A2.A2016057.h30v10.006.2016109163008.hdf<br>" OBJECT = RANGEBEGINNINGDATE\n",<br>" NUM_VAL = 1\n",<br>" VALUE = \"2016-02-29\"\n",<br>" END_OBJECT = RANGEBEGINNINGDATE\n",</A><br><br><br> |
| PM_MOD_17001 | 2017-01-01 | 2017-01-01 | Note | Leap second added 2017.001 On January 1st 2017, a leap second was added to the first granule of the year for both Terra and Aqua. As a result, the geolocation accuracy may be slightly impacted following the leap second adjustment. However, impacts to land products will be minimal as the addition of the leap second occurred in granules during night time acquisition or over the ocean and the acquisiton over land occurred about an hour later when geolocation accuracy has reached the stable acceptable error limit. The image below shows the profile of latitude in the track direction for a detector/observation around nadir. The x axis shows the line number and y axis is the latitude for the corresponding line and sample. The profile reveals noticeable deviation in the slope of the profile at start of granule and there after in every step as the latitude is interpolated from the 1-sec lag to the correct value over a period of one or two orbits. Review of tiled products from operational processing didn't reveal any noticeable geolocation shift in the tile with the first land observation for the day. |
| PM_MOD_16319 | 2016-12-14 | 2016-12-14 | Note | Night time granules labeled as day during TERRA Roll Maneuver During routine TERRA roll maneuvers a portion of night time data are flagged incorrectly as day time granules. This may result in incorrect downstream values in the snow and fire products. This note will document the incorrectly flagged granules detected during the TERRA roll maneuvers.<br><br> Terra MLC #169 DOY: 2016.323, granules 12:45, 12:50 flagged as 'both'<br> |
| PM_MOD03_16331 | 2016-11-29 | 2016-11-29 | Note | Missing geolocation data 2016.331 The Terra MOD03 granule 2016-331 17:25 contains fill values instead of valid geolocation data. Fill values in the geolocation data are also observed in the corresponding L1 MOD021KM granule 17:25. The images below show the geolocation loss in the latitude layer of MOD03 granule 17:25 and the corresponding L1B granule. The Data loss will impact L1 data and all downstream products. This data loss is a result of a packet being corrupted during the course of transmission of data from satellite to TDRS. The data gap occurs in granule 17:25 during a daytime orbit over Mexico and the United States. However, the day/night flag incorrectly reports 'both'. |
| PM_MOD10_16328 | 2016-11-23 | 2016-11-23 | Note | Incorrect value range reported in raw NDSI Metadata The TERRA and AQUA MODIS C6 MOD10_L2 and MOD10A1 snow products reports an incorrect range in the metadata for the Raw NDSI layer. The metadata reports the valid_range in the products as 0-10000, which applies only to the range for snow. However, the entire expected range of NDSI is -10000 to 10000. The current C6 metadata is incorrect. Below is an example of the metadata:<br><br> short NDSI(Along_swath_lines_500m:MOD_Swath_Snow, Cross_swath_pixels_500m:MOD_Swath_Snow)<br> NDSI:long_name = "Raw NDSI (Normalized Difference Snow Index) layer" <br> NDSI:units = "none" <br> NDSI:valid_range = 0s, 10000s <br> NDSI:scale_factor = 9.9999997e-05f <br><br> The image examples below show a spatial subset of the C6 MOD10_L2 Snow Cover and NDSI over Alaska. The NDSI shows negative values in red, which fall outside of the range reported in the metadata. Users should note that this will not make any difference to the quality of the science product. Work is in progress to fix this in C7. As a work around, it is suggested that since the C6 NDSI SDS reports NDSI values for all land and inland water pixels in daylight in a swath. Users should apply the masks, e.g. ocean, night, from the NDSI_Snow_Cover SDS to NDSI SDS when using the data. For additional details please see the C6 User <A href="https://landweb.modaps.eosdis.nasa.gov/data/userguide/snow_user_guide_C6_revised_draft_4.pdf">Guide.</A><br><br><br> |
| PM_MOD_16306 | 2016-11-02 | 2016-11-02 | Note | Data loss from SFE anomaly, 2016.306 (11.01.16) On DOY 306 the Terra Spacecraft experienced an SFE anomaly starting at 02:22:48z and ending at 02:26:45z. A data loss occurred approximately between 02:22:12z and 02:27:35z as a result of this issue. Granules 02:20 and 02:25 were found contain this data loss. This occurred during a night time orbit over the North Pole. The images below show the geolocation information and associated L1B Thermal and for granule 02:20, where the data loss can be observed. This data is not recoverable<br><br> |
| PM_MOD13_16301a | 2016-10-28 | 2017-01-04 | Pending | Non retrievals may have been incorrectly flagged in VI QA Due to a software bug pixels with no VI retrievals or fill values for VI in the 1km resolution 16-day VI product, MOD13A2, have been flagged as "highest quality" in the "VI Usefulness" bits. The following example shows images of a spatial subset of 16-day composite NDVI on left followed by corresponding subsets of the "MODLAND QA" bits in the "16-day VI Quality" datasets in the middle and the "VI usefulness" dataset on the right side. Pixels with no VI retrievals or Fill values in the left image of 16-day VI datasets are shown in black color. The corresponding pixels have been incorrectly flagged as "Blue:2:Pixel produced, but most probably cloudy" in the middle image, and flagged as "highest quality" in the right "VI Usefullness" image. The Pixels with no retrievals should be mapped as "Dark Blue:3:Pixel not produced due to other reasons than clouds" in MODLAND_QA. And "Black:15: Not useful for any other reason/not processed" in the VI usefulness flags.<br><br><br>NOTE: This issue has been resolved in the C6 forward processing from<A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=102"> day DOY 2017.241 and onwards.</A><br><br><br> |
| PM_MOD13_16301 | 2016-10-27 | 2018-01-04 | Pending | Some of the VI retrievals are flagged as good in MODLAND QA with lowest score for VI_Usefulness Due to a software bug some of the VI retrievals are flagged as good in the MODLAND QA bits (bits 0-1 = 00) within the 16-day Composite VI Quality SDS, with lowest score of 15 in the sds VI_Usefulness. A software patch is currently under testing and is expected to be operational in the forward processing soon. The following example shows images of a spatial subset of 16-day composite NDVI on left followed by corresponding subsets of the "MODLAND QA" bits in the "16-day VI Quality" datasets in the middle and the "VI usefulness" dataset on the right side. The black stripe in the image of "VI usefulness" corresponds to value 15, the lowest usefulness score. The corresponding pixels in the "MODLAND QA" has value "0" indicating good VI retrievals.<br><br><br>NOTE: This issue has been resolved in the C6 forward processing from <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=102">day DOY 2017.241 and onwards.</A><br><br><br> |
| PM_MOD03_16206 | 2016-08-22 | 2016-08-22 | Note | Terra geolocation anomaly 2016.206 There was a geolocation data anomaly in the C5 and C6 MOD03 geolocation data for granule 23:05 on data day 2016.206. This granule covers a daytime orbit over the Pacific Ocean. The first image below shows the L1B granule, and the second image shows the corresponding longitude data with the data anomaly. |
| AS_MOD_21285 | 2021-10-12 | 2021-11-19 | Closed | Terra SSR Reset 2021.265 (09.22.21) Missing Dailies On September 22, Terra MODIS underwent a <A href="https://landweb.modaps.eosdis.nasa.gov/displayissue?id=68">SSR reset event</A>, because of which significant science data outage was reported between 2021.265 11:05 and 2021.266 00:05. However, for some reason at MODAPS, the L2G PGEs failed to process the remaining 5-minute L2 granules that were acquired before the start of this SSR reset event. As a result most of the L2G or L3 dailies were not produced for this day. The Terra n-days and the Terra+Aqua combined products covering this day, have in the meanwhile been generated, excluding this day. But once we manage to troubleshoot and generate all the dailies for day 265, MODAPS will come back and re-process all the affected n-days and combined products that include this day. Please take note of this and be aware of any degradation in science quality in the n-day products, because of this one day missing in them.<br><br>Further updates will be provided once MODAPS manages to troubleshoot this day.<br><br><br><br><b><center>******************** <p style="color:red">Terra MODIS SSR Reset Event: UPDATE 11.19.21</p> ********************</b></center><br><br>Day 2021.265 as well as the affected n-days and combined products for Terra C6 and C61 were re-processed to include this day.<br><br> |
| PM_MOD10_16204 | 2016-07-22 | 2016-07-22 | Note | Dead Detectors Reflectance Band 6 The TERRA MODIS C6 MOD10_L2 snow product contains striping due to dead detectors in the L1B reflectance band 6. No such striping is seen in the C5 snow product. Although this is not an error in the C6, the difference between the C5 and C6 flagging in the snow product is due to the different treatment of the dead detectors in the C6 science algorithm. Work is in progress to fix this in the C6 forward processing.The following examples show the C5 and C6 MOD10_L2 daily snow cover product, where the striping can be observed in the C6. |
| PM_MOD35_16152 | 2016-05-31 | 2016-05-31 | Note | Possible degradation of Cloud Mask, user discretion advised Cloud Mask product uses daily NISE (Near Real Time ice and snow extent) data as input seed for global ice concentration and snow extent. NISE data from day 096 of 2016 (4/5) may have been degraded as posted by the data center at this url (http://nsidc.org/data/search/#keywords=NISE/sortKeys=score,,desc/facetFilters=%257B%257D/pageNumber=1/itemsPerPage=25). Though visual inspection of the cloud product do not reveal any obvious quality issues in the cloud mask, users are advised to exercise caution while using the product in their application. All downstream land products may be affected by degradation in the Cloud Mask. |
| PM_MODLWM_16127 | 2016-05-06 | 2016-05-06 | Note | Tile boundaries flagged as coastline Tile boundaries are flagged as coastlines in the LWM datasets stored in the C6 1km and 500m DEM files available from ftp://landsc1.nascom.nasa.gov/outgoing/c6_dem/. This has been traced to a possible coding error in the process used to generate the DEM files. The original LWM files available from the same ftp directory have been verified to be correct and do not have this error. Below are examples of the incorrectly flagged coastline boundaries (Magenta) observed in a spatial subset of the C6 1KM LWM in tiles h18v08 and h17v08.<br><br>Note: This issue is not observed in the original land water mask products (MOD44W) generated in MODIS tiles. The software process updating the DEM with the LWM information is currently being updated. DEM files will be regenerated after the software issue has been addressed. Users in need of the LWM product (MOD44W) can obtain the product from LAADS.<br><br><br><br>UPDATE: This issue has been resolved with a bug fix and the data has been reproduced.<br><br> |
| PM_MOD11_16083 | 2016-03-23 | 2016-03-23 | Note | Difference in LST from use of C6 snow prior to 06.17.2011 There could be some minor difference in LST from the use of the C6 snow as input in place of the C52 snow. This occurs from the start of the mission up until 06.17.2011. TERRA LST started using v6.4.14 on 06.17.2011.<br><br><br><br> |
| PM_MOD11_17226 | 2016-03-23 | 2016-03-23 | Note | LST from day 2017218 impacted by the DSC of Terra MODIS performed on 2017217 Day and Night LST retrieved using the Terra MODIS data acquired during the period 2017217 -23:15 through 2017218 - 14:20 may have been negatively impacted by the drift in the operational temperature of the Cold Focal Plane assembly hosting the thermal bands. A deep space calibration was performed on Terra MODIS on day 207217 starting at 23:15:46 GMT and ending at 23:51:40. The CFPA temperature returned nominal at about 14:20 on the following day. The following two images are global browses of day time and night LST from day 218. The sparse retrieval on the eastern hemisphere for the day LST (image on the left) and the sparse retrieval on the night LST (image on the right) on the western hemisphere is the result of the non-nominal operating temperature of the CFPA.<br><br><br><br> |
| PM_MOD_16049 | 2016-02-18 | 2016-04-19 | Note | Terra MODIS Enters SAFE MODE 2016.049 On 02.18.16 (2016.049) the Terra spacecraft entered safe mode on DOY 049 at 1433z. Terra MODIS was transitioned to science mode on Feb 24, 2016 (day 055) after being in safe mode since Feb 18, 2016 (day 049). Though the data is currently being acquired and processed at MODAPS and NRT, users are advised to exercise caution in using the products in any application. Products from DOY 055 to 058 might have been severely degraded due to abnormal operating temperature for the SWIR and LWIR FPA and hence products may not be usable in any application. Though the focal plane temperatures have reached the stable operating value as of day 059 some products may still have been impacted by the increased noise in some of the detectors in the thermal bands. Users are requested to exercise caution in using the products until further notice.<br><br><b>NOTE (Current Status): Terra MODIS has returned to science mode operation on Feb 24, 2016 following transition of the satellite and instrument to SAFE-HOLD on Feb 18. MODAPS started processing of Terra MODIS on March 07, 2016. Data from day 2016059 and onwards is being processed. No instrument data is available for days 049 through 55 and data not usable for day 055 through 058, the period 2/24 through 2/27 (focal planes had not reached the operational temperature). All land data products from the post safe-hold period are expected to be of nominal quality, however n-day products with time periods overlapping the period of 050 - 058 would be degraded from use of less than normal number of input days.</b><br><br><br><br>Below is an example of the comparison for the MOD17A2-Gross Primary Productivity 8-Day L4 Global 1km on day 2016.057, and 073. Due to the safe mode period, The DOY 057 product was run with less than expected number of days as input, resulting in lower than normal productivity on a global scale when compared to DOY 073.<br><br><br> |
| PM_MOD09_16032 | 2016-02-01 | 2016-02-01 | Note | MOD09 differences in internal cloud and internal snow flags Snow and cloud flags generated within the MOD09 process stored as the 'internal snow' and 'internal cloud' in the '1km Data state QA' of Surface Reflectance, in addition to storing the snow and cloud flag from MOD35, the MODIS cloud product. The internal snow and cloud flags though are mostly correct, there could be errors from snow-cloud confusion. The occasional error in these flag though is not known to have any negative impact on the retrieved reflectance, work is in progress to improve the performance of the algorithms. Yet these flags are not meant to be used as replacement for cloud or snow product. Users and downstream processes requiring accurate cloud and snow are advised to use the MODIS cloud (MOD35) and snow products (MOD10).<br><br>These internal flags though are mostly correct, often these inaccuracies are observed as snow over amazon, or snow in some area of North America during a summer period. The examples provided below show a few of these known inaccuracies.<br><br>Examples below are generated from a MOD09 granule over North America during the summer period 2015.198 (July, 17th). The images on the left show MOD35 reporting snow and cloud clear condition. The images on the right show the internal snow and internal cloud mask reporting no snow and cloudy conditions.<br><br> |
| PM_MOD02_15151 | 2015-06-24 | 2015-06-24 | Note | Dead Detector in Emissive band 30, 2014.151 Starting data day 2014.151, MODIS Terra L1B contains striping in Band 30 from a detector flagged as in-operable or dead. L1B files contain fill value of 65531 for this detector in Band 30 of L1B product file (MOD021KM). Following example shows false color images of band 30 from DOY 2014.150 and 2014.151. The image on the left from DOY 2014.150 looks normal without any striping artifact as all the detectors were functioning. The image on the right from DOY 2014.151 shows striping artifact from fill value corresponding to dead detector #4. |
| PM_MOD35_15154 | 2015-06-03 | 2015-06-03 | Pending | Terra Cloud Mask (MOD35) Threshold Change In April 2015, it was noticed that recent Terra cloud top pressure data contained ocean regions with very high incidence of low clouds. This was traced to false clouds being reported by the cloud mask (MOD35). In turn, this was found to be the result of errors in the 8.6-11 µm brightness temperature difference (BTD) high (ice phase) cloud test. Many clear pixels were being flagged as cloudy by the offending test. An adjustment to the 8.6-11 µm test thresholds was provided to fix the problem. New thresholds are considered to be appropriate for data beginning on January 1, 2015, although the problem has existed since late 2013 or early 2014, and has gotten steadily worse since then. It is unknown whether or not the problem has stabilized in recent months. The figures below show an example of the test results before and after the thresholds were adjusted. |
| PM_MOD_00252 | 2015-05-22 | 2015-05-22 | Note | A Terra MODIS data loss due to calibration activity 2000.252 On 09/08/00, Terra MODIS experienced a data outage due to calibration activity over portions of South America. Below is an example of the global browse image where the data loss is observed. For detailed information on the calibration activity users can reference MCTS <A HREF="http://mcst.gsfc.nasa.gov/modis-events-categories/routine-calibrations?event_date[value][year]=2000&modis_mission=61&page=2"> records of MODIS Events Routine Calibrations. </A> |
