Drifting with the GPS drift

When preparing the previous post on GPS drift I wondered what would happen if you would drift along with the drift. Yesterday I had 30 minutes to spare and I gave it a try. I went to the park, switched on the GPS in the middle of the field, stood still and waited for the device to 'move' and then I followed its direction. This caused the direction to change and I proceeded to follow the new direction, etc. etc. In effect GPS drift only provided a first random direction before I created a feedback loop where I was following myself with a delay. Often the direction switched between opposite cardinal directions with great speed and several times I got dizzy by trying keeping up, sometimes I just had to let the thing come to rest before resuming the chase. Disorienting! 

A GPS night drift

After my complaint in a previous post about my GPS's failure to capture my postal rounds with the accuracy I was hoping for, three readers came up with possible explanations. I still think it has to do with recording rates (there is more time between 'clicks' than it takes me to walk in and out of a front garden) rather than any technical or strategical reason. But I was intrigued by the suggestion of GPS drift, the phenomenon of a GPS device recording movement while it is just laying motionless on a table somewhere. So overnight I left my device next to the window recording while I was sleeping and the above shows its paths, a random walk with one outlier travelling 588 meters. The squares blame technical inaccuracies, but I prefer another explanation: the earth is playing while the satellites are obeying the routines of the military-industrial complex.