Optical Physics Company (OPC) has developed and matured an interferometric star tracker technology which can provide the accuracy required for a Handheld Celestial Navigation System (HCNS) to serve as an alternate when primary GPS systems are denied. Innovative research and development is needed to incorporate this technology with other components into a HCNS which can address the eleven (11) design considerations in the SOCOM203-002 solicitation such that Soldiers on the ground have reliable and accurate non-GPS navigation capabilities. A key challenge in the HCNS development is for it to provide navigation when a Soldier is stationary, walking, running or driving in a vehicle