What exactly is the Global Positioning System?
Gene Morgenthaler who recently began employment with KRWA offers this explanation of the Global Positioning System (GPS). GPS is a satellite positioning system developed by the U.S. Department of Defense (DoD). This constellation of satellites was established by the DoD for military purposes, but has since been adopted by the civilian sector for general surveying including ground control measurements. The GPS constellation is comprised of 24 satellites orbiting the Earth twice a day, continuously broadcasting L-Band signals. There are typically more than 24 satellites in orbit as new satellites are launched in order to replace aging ones. Each broadcast signal contains the satellite’s identification, a GPS time stamp, and location information. The signal of the satellite is compared to the signal generated by the GPS receiver. The signal shift, along with the time it takes for the satellite signal to reach the ground receiver, is used to determine the distance from the satellite and su
