GPS Beacons
Locations of GPS Beacons round the world. This site lists the locations of Trimble GPS Beacons around the world. You select your own country from the menu to see a list of relevant Beacons. GPS Beacons are designed to improve marine navigation by GPS and to reduce the annoying error added to the signals by the US Military.

How a GPS Receiver Works
A useful site that explains how GPS sets work. The text is clear and well written, providing a good introduction to,and overview of, the way a GPS handset can tell you your location.

How GPS Works
The site contains three good tutorials covering how GPS functions, how to use GPS, and also Differential GPS. This is the same company that provided the GPS Beacons link.

How To use GPS
A very useful site that explains how to use GPS in a slightly more advanced way than simply wandering around looking at an arrow on a lcd display. It considers how to conduct a static survey, an RTK survey and setting up a base station. This material is suited to teachers and advanced students.

Scanex
Scanex is a commercial company that specializes in satellite remote sensing, data acquisition and distribution. They provide free archived images from the Resurs-01 satellite and from the Mia Space Station.

Talking about the GPS
Another informative guide to GPS that would be of great benefit to people new to GPS technology, or teachers about to use GPS with a class. The guide doesn't go into great detail but provided a clear explanation of the different parts of a GPS system. A good introductory document.

US Coast Guard
Frequently asked questions about GPS navigation are answered by the US Coast Guard. This site provided very good information in the form of answers to frequently asked questions.