Links
[1] http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html
[2] http://www.ngs.noaa.gov/PUBS_LIB/develop_NSRS.html
[3] http://www.ngs.noaa.gov/FGCS/tech_pub/GeomGeod.pdf
[4] http://docs.lib.noaa.gov/noaa_documents/NOS/NGS/Geom_Geod_Accu_Standards.pdf
[5] http://www.navcen.uscg.gov/pdf/dgps/dgpsdoc.pdf
[6] http://www.photolib.noaa.gov/
[7] http://www.ngs.noaa.gov
[8] http://www.ngs.noaa.gov/CORS/
[9] http://gps.losangeles.af.mil/
[10] http://www.trimble.com/survey_wp_gpssys.asp?Nav=Collection-27596
[11] http://www.aimil.com/Resources/ResourceFile/107_r-track_wp_022543-078_0304_lr.pdf
[12] http://www.nasm.si.edu/gps/
[13] http://www.ngs.noaa.gov/CORS/Presentations/CORSForum2005/Richard_Snay_Forum2005.pdf
[14] http://www.navcen.uscg.gov/?pageName=dgpsMain
[15] http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/faq/gps/
[16] http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/gps/howitworks/
[17] http://www.edu-observatory.org/gps/gps_accuracy.html
[18] http://gpsinformation.net/exe/waas.html