GPS-Based User Equipment for all Altitude Tracking

Studies and test data previously collected have shown that GPS tracking can be used for space vehicles at high altitudes, including up to geo-synchronous (GEO) satellite orbits. GPS tracking could significantly simplify implementation of autonomousGuidance, Navigation, and Control (GN&C) in upper stages and satellites. Even without full autonomy, GPS tracking has the potential of shortening the orbit determination process by using a single contact to determine position after a satellite maneuver.Under Phase I of this SBIR a review was conducted of all space qualified GPS receivers and their flight experience and detailed design options were considered for a low cost, low power, lightweight, miniaturized design of a GbUE suitable for supportingmultiple space missions including GPS metric tracking during launch, orbit determination during transfer or geostationary orbits, and high accuracy navigation, attitude control and timing. Under the proposed Phase II effort, we will design, build and testa brass-board GbUE based on a software reconfigurable architecture and demonstrate its performance during different space operational environments using a GPS signal simulator.