GPS Study

GPS Signal Variation Shows Structure

What happens when you hold a GPS antenna still for 75 days, and record the latitude and longitude data? Well you get a record of the motions of the GPS system (physical as well as gravitational and signal propagation related)

Oh, and 'random walk' data- you find it is not so random after all. When you look at the data over an extended period of time, you find embedded frequencies, with well defined structure.