Gizmag Comment Feed: GPS satellites tell us where we are, but what tells them where they are?

Gizmag Comment Feed: GPS satellites tell us where we are, but what tells them where they are? http://www.gizmag.com Global Positioning System (GPS) devices have permeated society to the point where millions of us rely on them daily for directions, locations and traffic avoidance (if only they could tell me where I left my car keys). GPS satellites send signals to a receiver in your handheld or car-based GPS navigator, which calculates your position on the planet based on the location of the satellites and your distance from them. The distance is determined by how long it took the signals from various satellites to reach your receiver. But have you ever thought what tells the GPS satellites where they are in the first place? en gizmag.com Comment on 'GPS satellites tell us where we are, but what tells them where they are?' by Travis http://www.gizmag.com/gps-satellite-location/13237/#comment-9973 http://www.gizmag.com/gps-satellite-location/13237/#comment-9973 Tue, 03 Nov 2009 17:42:45 -0600 Comment on 'GPS satellites tell us where we are, but what tells them where they are?' by SF http://www.gizmag.com/gps-satellite-location/13237/#comment-9934 http://www.gizmag.com/gps-satellite-location/13237/#comment-9934 Mon, 02 Nov 2009 08:21:46 -0600