GPS/GLONASS/Galileo information and data
Canadian Active Control System (CACS data and service): http://www.geod.nrcan.gc.ca/htmlpublic/GSDproducts-Guide/CACS/English/cacstest.html
Geodetic Survey Division of Geomatics Canada: http://www.geod.nrcan.gc.ca/index_English_text_based.html
Galileo EC page: http://www.Galileo-pgm.org/
Galileo World magazine: http://www.galileosworld.com/
GPS World magazine: http://www.gpsworld.com/
International GPS Service for Geodynamics (RINEX and precise ephemeris data): http://igscb.jpl.nasa.gov/
International Terrestrial Reference Frame (ITRF): http://large.ensg.ign.fr/ITRF/index-old.html
Ministry of Defence of the Russian Federation (GLONASS Web page): http://www.rssi.ru/SFCSIC/English.html
National Imagery and Mapping Agency (NIMA): http://164.214.2.59/nimahome.html
Navtech Seminars and GPS Supply: http://www.navtechgps.com/
UNB Internet resources: http://gauss.gge.unb.ca/GPS.INTERNET.SERVICES.HTML
University Navstar Consortium (UNAVCO data and service): http://www.unavco.ucar.edu/
U.S. Coast Guard Navigation Center (GPS NANU, GPS Almanac, FRP, and others): http://www.navcen.uscg.gov/
U.S. Continuously Operating Reference Station (CORS data): http://www.ngs.noaa.gov/CORS
U.S. National Geodetic Survey: http://www.ngs.noaa.gov/index.shtml
U.S. National Geodetic Survey GEOID page: http://www.ngs.noaa.gov/GEOID
U.S. National Geodetic Survey Orbit data: http://www.ngs.noaa.gov/GPS/GPS.html
U.S. Naval Observatory (GPS timing data and information): http://tycho.usno.navy.mil/gps_datafiles.html
GPS manufacturers
Applanix Corporation (integrated systems): http://www.applanix.com/
Integrinautics (pseudolites): http://www.integrinautics.com/
Leica: http://www.leica.com/
Magellan Corporation (Ashtech precision products): http://www.ashtech.com/
NovAtel: http://www.novatel.ca
Pacific Crest Corporation (radio link systems): http://www.paccrst.com/
SOKKIA Corporation: http://www.sokkia.com/
Trimble Navigation: http://www.trimble.com/
