Abstract: Described herein is a GPS pet containment system is that generally self contained within a collar. However, the collar includes a battery power source, a microcontroller powered by the battery power source, a global positioning system (GPS) interfaced to the microcontroller and an accelerometer interfaced to the microcontroller. The GPS operates to provide collar location information on a periodic basis while the accelerometer provides collar dead reckoning location information on a substantially continuous basis. The dead reckoning location information is acquired by integrating the acceleration value provided by the accelerometer over sub-second time intervals.