On July 17, 1995, the Global Positioning System (GPS), the world's first space-based satellite navigation system is declared operational. GPS provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.
T. Collaboration, K. Bechtol, A. Drlica-Wagner, E. Balbinot, A. Pieres, J. Simon, B. Yanny, B. Santiago, R. Wechsler, J. Frieman and 83 other author(s). (2015)cite arxiv:1503.02584Comment: 33 pages, 12 figures, 3 tables. Submitted to ApJ. Readers may be interested in the concurrent work by Koposov, Belokurov, Torrealba, & Evans. Indirect dark matter search results are presented in Drlica-Wagner, Albert, Bechtol, Wood, Strigari, et al. (The LAT and DES Collaborations).