Here we see an image of the Washington, D.C. area taken with the Landsat satellite. The dates of the images are from 1986, 1990, 1996, and 2000. For over 26 years, Landsat images have been used to help urban planners understand where growth is taking place and help geographers evaluate how different urban planning programs effect population growth and land use.
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 8.0.0.0.0