Moderate Resolution Imaging Spectroradiometer (MODIS) refers to two instruments currently collecting data as part of NASA's Earth Observing System (EOS) program. The first MODIS instrument was launched on board the Terra satellite on 18 December 1999, and the second was launched on board the Aqua satellite on 4 May 2002. A key instrument in the EOS mission, the MODIS instrument provides high radiometric sensitivity (12 bit) in 36 spectral bands ranging in wavelengths from 0.4 µm to 14.4 µm. MODIS obtains measurements with spatial resolutions of 250 m (bands 1 and 2), 500 m (bands 3-7), and 1000 m (bands 8-36) using a continuously rotating double-sided scan mirror.

In short, the MODIS instruments provide calibrated, geolocated radiance data from individual bands, and a series of geophysical products from land, ocean, and atmosphere disciplines that can be used for studies of processes and trends on local to global scales. This data helps scientists understand the Earth as a system, facilitating their ability to predict global climate changes and to differentiate between the impact of human activities and natural activities on the environment.

The National Snow and Ice Data Center (NSIDC) archives and distributes snow and sea ice products derived from MODIS Level 2 swath data and Level 3 gridded composites. Please see the MODIS Data at NSIDC Web site for tools to order and work with the data, information regarding the availability of data products, how to obtain guide documentation, FAQs, and other related MODIS information.