Terra MODIS Level-1A Geolocation Data, version 1

Level 1A (L1A) data are reconstructed, unprocessed instrument data at full resolution, time-referenced, and annotated with ancillary information. This ancillary information can include radiometric and geometric calibration coefficients and georeferencing parameters (e.g., platform ephemeris).
The Geolocation (GEO) collection provides terrain-corrected geolocation, viewing geometry, and navigation information required to accurately map satellite observations to Earth coordinates. The products include per-pixel latitude and longitude, surface height, solar and sensor zenith and azimuth angles, along with quality flags describing geolocation validity. In addition, scan-level timing, spacecraft attitude, and orbital navigation parameters are provided to support precise georeferencing and downstream processing. The GEO data are distributed in self-describing data formats and are intended to be used in conjunction with Level-1 radiance products to enable the generation and analysis of higher-level geophysical data products.