Regular readers know I experiment with location-based technology quite often. Some time ago, I turned on Google Latitude in my Sprint EVO and started collecting data about my whereabouts. I looked at it all on a map and – as opposed to being concerned about my privacy -- took solace in the fact that I would have a strong alibi if anyone needed to know my location on a certain date and time. That said, looking back over the past 30 days, I noticed some strange data on the map about places I had presumably been.
Being well trained to first assume that the data is accurate, I asked myself how that could be. Was my phone being used by someone else? Was I sleepwalking? Had I been abducted by aliens? Tinker, Taylor, Soldier, Spy … is this me and if so why? On one day in particular, I apparently based my operations out of a vacant house on the other side of town. Later that day, I went to a riverboat casino. What was going on? Was I living a double life?
Based on the time stamps of the data, it was clear that the errant locations were some kind of aberration. Maybe because it was a free app, I wasn’t getting access to enough GPS information … or maybe the vacant house was a Sprint PCS tower that the system was using to triangulate my location.
Looking for a solution, I came across Latify Mobile. Latify is a client for Google Latitude that allows one to customize polling intervals and the like. After investing 10 minutes on a walk (for the sake of research, of course), I collect 17 new waypoints. The accuracy is almost 100 percent, except for similar aberrations: I again was transported through space and time momentarily into someone’s house a quarter mile away and then, for only about 1,000 milliseconds, I was downtown in the county jail.
In digging deeper, it is obvious that the errors which can lead to false data in GPS receivers are too numerous to discuss. It would be easy for most software to fix the errors; a person walking or even driving a car can’t appear five miles away and then back at the original location in a matter of five seconds. I have to believe that most well-developed GPS software is already doing this kind of aberration detection.
All of this is important because the next wave of Unified Communications software will need to make decisions based on what you are doing at any given moment in time. The use of GPS and accelerometers is expected to create new presence states such as walking, running, driving, flying, etc.—all presumed from whether or not your phone is moving and how fast. The technology isn’t quite there yet — unless there is a presence state called “time travel,” in which case I guess I can’t rely on GPS data to be my alibi.
