GPS has evolved from a once purely militaristic application into a cornerstone technology for all. It has been integrated into the very fiber of civilization and stands as the bedrock of modern navigation. Whether one is navigating unmarked country roads, tracking a person’s whereabouts, flying on a commercial airliner or developing autonomous vehicles; they all rely on the same principles of INS/GPS navigation. The sobering consequence of this shared technology, however, is that whether by necessity, ill intent or environmental conditions, GPS signals can all be taken away, without warning, for extended periods of time. How well one navigates in a GPS denied environment depends mostly on the quality of IMU being utilized.