In this effort Cybernet developed a system that uses inexpensive MEMS accelerometers, gyroscopes, magnetometers, and vehicle wheel sensors coupled with high fidelity models of the earth’s gravity and magnetic fields. Using low-cost, high performance digital signal processors (DSPs), sophisticated mathematical filters can produce high fidelity position and heading information. The use of these passive sensors is key to providing POS/NAV solutions in cases where GPS signals are unavailable due to satellite signal availability problems, enemy jamming conditions, and obstacles such as buildings common in “urban canyon” environments.