A newer version of this visualization can be found here.
This animation shows the orbits of NASA's current (as of May 2013) fleet of Earth remote sensing observatories. The satellites include components of the A-Train (Aqua, Aura, CloudSat, CALIPSO), two satellites launched in 2011 (Aquarius, Suomi NPP), and nine others (ACRIMSAT, SORCE, GRACE, Jason 1 and 2, Landsat 7, Landsat 8, QuikSCAT, TRMM, and EO-1). These satellites measure tropical rainfall, solar irradiance, clouds, sea surface height, ocean salinity, and other aspects of the global environment. Together, they provide a picture of the Earth as a system.
This is an update of visualization #3725. It was created for display on the NASA Center for Climate Simulation (NCCS) hyperwall, a 5 x 3 array of high-definition displays with a total pixel resolution of 6840 x 2304. The orbits are based on orbital elements with epochs in April of 2013. The visualization spans twenty-nine hours, from 04:10 UT on April 14, 2013 to 09:24 UT on Aril 15, 2013.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 22.214.171.124.0