The MODIS Land products are generated in a hierarchy of processing levels: retrieved geophysical parameters at the same location as the MODIS instrument data (Level 2), earth-gridded geophysical parameters (Level 2G and Level 3), and earth-gridded model outputs (Level 4). The smallest unit of MODIS Land data processed at any one time is defined at Level 2 as a granule, and at Levels 2G, 3 and 4 as a tile.

A granule corresponds to 5 minutes of MODIS sensing such that there are approximately 2000 MODIS 1 km detector scan lines per granule. MODIS senses over a field of view of approximately 110 degrees. Because of the curvature of the Earth and the MODIS scanning geometry, the scan lines are elongated so that the geographic coverage of a granule is approximately 2340 x 2330 km in the across and along track directions respectively. The MODIS Land Level 2 products sensed over a 12 hour period data are binned without resampling into an intermediate data format referred to as Level 2G (Wolfe et al., 1998). The Level 2G format provides a convenient geocoded data structure for storing granules and enables flexibility for subsequent temporal compositing and data projection. Level 2G products are temporally composited to make daily, 8-day, 16-day, and 32-day Level 3 and Level 4 tile products.

The tile products (Levels 2G-L4) are defined in a global non-overlapping grid. Globally, there are 460 tiles, of which 326 contain land pixels. Each tile has fixed Earth-locations covering an area of approximately 1200 x 1200 km (10 x 10 degrees at the equator). All collection 1 and 3 MODIS Land tile products are defined in the equal area Integerized Sinusoidal projection (Rossow and Garder, 1984). All collection 4+ MODIS Land tile products are defined in the equal area Sinusoidal projection (Snyder, J.P. 1987). In addition the snow and sea-ice products are defined in the Lambert Azimuthal Equal Area projection (Snyder, J.P. 1987) using a different tiling scheme. The tile vertical and horizontal coordinates are reflected in the product filename.

• Table of the L2G/L3/ L4 Integerized Sinusoidal Tile Bounding Coordinates (updated 8/11/2000).
• Integerized Sinusoidal Projection parameters for the General Cartographic Transformation Package.
• Table of the L2G/L3/ L4 Sinusoidal Tile Bounding Coordinates (updated 11/14/2003).
• Sinusoidal Projection parameters for the General Cartographic Transformation Package.

References:

• Snyder, J.P., (1987), Map Projections - a Working Manual, U.S. Geological Survey Professional Paper 1395, Washington, DC, United States Government Printing Office.
• Wolfe, R.E., Roy, D.P., Vermote, E.F., 1998. The MODIS land data storage, gridding and compositing methodology: Level 2 Grid, IEEE Transactions on Geoscience and Remote Sensing, 36:1324-1338.
• Rossow, W.B. and Garder, L., (1984), Selection of a map grid for data-analysis and archival, Journal of Climate and Applied Meteorology, 23: (8) 1253-1257.

Illustration of a day of MODIS sensing showing MODIS Land L2 granules.

Illustration of the MODIS Land L2G/L3/L4 tile grid (provided by Jacques Descloitres).