A newer version of this visualization can be found here.
This animation shows the orbits of NASA's current (as of January 2014) 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 eleven others (ACRIMSAT, SORCE, GRACE, Jason 1 and 2, Landsat 7, Landsat 8, GPM, 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 #4070. 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. Some simulated orbits where added, such as GPM, as they had not launched at the time these visualizations were created.
Two versions of this visualization are provided. The first colors the orbits blue except that TRMM is colored green and GPM is colored red. The second visualization colors all of the orbits blue.
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