GPS Status Information from US Naval Observatory  
   Via ftp.
   ftp://tycho.usno.navy.mil/pub/gps/

GPS Precise Orbits  
   Global Positioning System satellite ephemerides ("orbits") information for the general public, from US NOAA. GPS precise orbits are derived using 24 hour data segments from the global GPS network. An informational summary file is provided to do
   http://www.ngs.noaa.gov/GPS/GPS.html

Satellite Navigation and Positioning Group (SNAP)  
   SNAP is Australia's largest academic GPS research group specialising in high precision GPS technology and applications.
   http://www.gmat.unsw.edu.au/snap/snap.htm

GPS Kwajalein  
   GPS Ground Station on Kwajalein Island, photographs of the island and site. Links to others GPS sites.
   http://www.angelfire.com/ab/gpskwaj/index.html

GPS Control Base Station on Internet  
   GPS Base Stations located in New Zealand, Australia, and New Guinea. Download GPS data files for $40-$70 per day.
   http://www.gpscontrol.com/

Outdoor Gear Reviews  
   GPS receiver comparisons.
   http://gearreview.com/navreviews.asp

Septentrio Satellite Navigation  
   Dual frequency GPS & GLONASS, as well as EGNOS, WAAS and MSAT based on an in-house single baseband processor.
   http://www.septentrio.com/

Wing Way Systems  
   Navigation-Wonder, a shareware GPS mapping navigation software including voice response system [Windows].
   http://www.vader-abraham.com/gpssoft.htm

Australian Global Positioning Systems Society  
   A free membership society to bring together the delegates, sponsors, and exhibitors for the Satellite Navigation Conference and to foster, develop, and assist the Global Positioning System disciplines.
   http://www.gps-society.org/

Internet-based Global Differential GPS  
   C-language software package for GPS-based real-time positioning and orbit determination. Includes system overview, technical papers, and a live demo .
   http://gipsy.jpl.nasa.gov/igdg/index.html

Travel by GPS  
   Downloadable free GPS maps for travel adventures, self-guided tours, and outdoor activities. Map data includes waypoints and routes for use with handheld GPS and car navigation systems.
   http://www.travelbygps.com/

GPS Applications Exchange  
   GPS technology usage world-wide is featured. GPS application stories are accessed by geographic regions. GPS tutorials are available to enhance understanding.
   http://gpshome.ssc.nasa.gov/

Hyperbolic Positioning Algorithm  
   An algorithm for obtaining an exact solution for the three dimensional location of a mobile given the locations of four fixed stations (like a GPS satellite or a base station in a cell) and the signal time of arrival (TOA) from the mobile to each statio
   http://ralph.bucher.home.att.net/project.html

GPS Deformation Monitoring  
   Objective is the development of a system for rapid and inexpensive monitoring of unstable slopes, such as pit walls, earth\rock slopes and dam walls using global satellite positioning technology.
   http://www.cage.curtin.edu.au/~geogrp/research/res-mon.html

David L. Wilson's GPS Accuracy Web Page  
   Global Positioning System Accuracy
   http://users.erols.com/dlwilson/gps.html

The Global Positioning System: The History of GPS  
   The history and story of how the Global Positioning System evolved from the development of the world's most accurate timepieces, atomic clocks, by physicists looking into the nature of time. Adapted from an article written by MIT scientist Daniel Kleppne
   http://www.beyonddiscovery.org/content/view.article.asp?a=458

GPS Site from Univ of Texas  
   Global positioning system overview and bibliography.
   http://www.colorado.Edu/geography/gcraft/notes/gps/gps_f.html

GIS Services  
   Specializes in ArcView GIS training and provides commodities, services and training for implementing and integrating solutions with GIS, GPS, AVL, internet mapping and satellite imagery.
   http://gisservices.net/

Cetus GPS  
   Navigation, tracking and field data collection software for PalmOS handhelds.
   http://www.CetusGPS.dk/

The GPS Waypoint Base  
   Non-commercial project allowing the collection or submission of GPS waypoints.
   http://www.waypoints.de/

Emily Programme  
   A system study researching the coupling of terrestrial positioning and the satellite-based positioning.
   http://www.emilypgm.com/

USCG Navigation Center  
   GPS, DGPS, LORAN-C, OMEGA, navigation systems, GPS navigation, DGPS navigation.
   http://www.navcen.uscg.gov/

The National GPS Network  
   Resource from the UK Government intended for GPS-equipped surveyors, and Geographic Information Systems (GIS) developers who work with Ordnance Survey (OS) mapping. Includes the Passive Station Database, Active Station RINEX Data, and Coordinate Converter
   http://www.gps.gov.uk/

GPS ActiveX  
   Download information into a Visual Basic application or web page. Garmin, Magellan, Navman or any NMEA 0183 enabled GPS supported. UTM, SPCS, British National Grid, and most other national coordinate systems supported. [Windows and Pocket PC].
   http://franson.biz/gpstools/

Wayhoo.com  
   Database of geographical waypoint information and utilities for GPS/GIS users.
   http://wayhoo.com/

GPS Information  
   Mehaffey, Yeazel and DePriest's site provides dozens of reviews and technical articles on GPS receivers and software, and a huge list of links.
   http://gpsinformation.net/

Chartracer Software  
   Cartographic Software is for making moving maps on which GPS data from a serial port are plotted. Data are tracked remotely via CDPD modems and internet sites.
   http://www.chartracer.com/

GENESIS  
   Suite of data services that brings together the new Earth science products to be produced by spaceborne Global Positioning System (GPS) receivers. It serves mainly as a database for GPS occultation observations.
   http://genesis.jpl.nasa.gov/

GPS Clocks for Computer Time Synchronization  
   Learn about how to use GPS for computer time synchronization. We offer a GPSClock (for computer use) that's accurate to a millionth of a second. Ideal for running a stratum one NTP server.
   http://www.gpsclock.com/

RLA GeoSystems  
   Source for GPS information and training. Trimble ProXRS and GeoExplorer3 receivers, top 10 websites, GPS for educators and free help.
   http://www.rlageosystems.com/

GPS by Globespotter  
   GPS education, news, hardware, software, and links. Digital mapping.
   http://globespotter.com/

GPS Discounts for Educators  
   GPS special pricing for Trimble GeoExplorer 3 and ProXR/XRS educator kits. GPS education and training courses. Tutorials to learn about the GPS system. GPS consulting and course development.
   http://www.gps4educators.com/