On April 15, 2004, David Lockwood completed a GPS survey of the Sylvia Lake shoreline. On the chart below, you can find the Latitude and Longitude of a number of locations around Sylvia Lake.
When people talk about “a GPS,"” they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth-orbiting satellites (24 in operation and three extras in case one fails). The U.S. military developed and implemented this satellite network as a military navigation system, but soon opened it up to everybody else.