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Terra and Aqua Platforms (Satellites) carrying the MODIS Instruments

Approximately the size of a small school bus, both the Terra (originally known as EOS AM-1) and Aqua (originally known as EOS PM-1) satellites or platforms carry instruments that take coincident measurements of the Earth. MODIS (or Moderate Resolution Imaging Spectroradiometer) is a key (flagship) instrument aboard the Terra and Aqua satellites. Terra's orbit around the Earth is timed so that it passes from north to south across the equator (descending node) in the morning, while Aqua passes south to north over the equator (ascending node) in the afternoon. Both satellites are in a circular sun-synchronous polar orbit that navigates the daylight (sunlit) side of the Earth approximately every 99 minutes. Terra MODIS and Aqua MODIS are viewing the entire Earth's surface every 1 to 2 days, acquiring data in 36 spectral bands, or groups of wavelengths. These data will improve our understanding of global dynamics and processes occurring on the land, in the oceans, and in the atmosphere. MODIS is playing a vital role in the development of validated, global, interactive Earth system models able to predict global change accurately enough to assist policy makers in making sound decisions concerning our environment.

•    Terra Platform (AM Overpass) 
•    Aqua Platform (PM Overpass) 

Terra and Aqua Maneuvers

•    Terra & Aqua Maneuvers

Terra and Aqua Orbit Tracks

•    Terra Orbit Tracks
•    Aqua Orbit Tracks

Day of Year Calendar (useful for converting 'day of year' in the HDF filenames to month & day)