1. Bar-Sever Y, Young L, Stocklin F, Heffernan P, Rush J (2004) The NASA global differential GPS system (GDGPS) and The TDRSS Augmentation Service for Satellites (TASS), ESA 2nd workshop on navigation user equipment, December 2004 Noordwijk, The Netherlands
2. Beutler G, Rothacher M, Schaer S, Springer TA, Kouba J, Neilan RE (1999) The International GPS Service (IGS): an interdisciplinary service in support of earth sciences. Adv Space Res 23(4):631–635
3. Creel T, Dorsey AJ, Mendicki PJ, Little J, Mach RG, Renfro BA (2006) The legacy accuracy improvement initiative, GPS World 17/3,20
4. Feng Y (2001) An alternative orbit integration algorithm for GPS based precise LEO autonomous navigation. GPS Soliut 5(2):1–11
5. Gill E, Comparison of the performance of microprocessors for space-based navigation applications (2005), DLR/GSOC TN 05–02, Deutsches Zentrum für Luft- und Raumfahrt, Oberpfaffenhofen