NASA Logo, National Aeronautics and Space Administration

The Afternoon Constellation

Constellation Flying - A-Train

Swaths and Footprints

This image shows the A-Train satellites as if looking down on the entire constellation from orbit. The satellites that make up the A-Train travel from south to north (bottom to top in this image). The colorful bars across each satellite illustrate the swath of several instruments. From this remote perspective, the instruments with smaller footprints are barely visible. The table in this illustration lists each satellite, selected instruments, and the width of each swath in kilometers.

This image shows the overlapping footprints of several of A-Train instruments (colors correspond to those in the above image) superimposed on a close-up image of Washington, DC. The purpose is to give a sense of how, over the course of an orbit, the swath of each instrument overlaps the others, allowing for the nearly simultaneous observations of the same location or event that are crucial to the science of the A-Train. This close-up perspective also brings the challenge of constellation flying into sharper focus. In order to successfully overlap science measurements from different A-Train instruments, each with varying footprints and resolutions, each member of the A-Train must strictly maintain its position in the constellation.

A-Train Fact