Description: The need for science-grade Position, Navigation, and Timing (PNT) sensors that are low Size, Weight, and Power (SWaP) is well recognized. The ability to provide precise positioning and pointing in real-time is a capability needed for formation flying, rendezvous and proximity operations, and radio and laser altimetry. To address this need, Emergent Space Technologies will develop a low SWaP codeless GPS receiver that will be capable of precise and real-time orbit determination. Currently, precise orbital determination is performed on the ground since real-time GPS differential corrections won't be available on orbit until they are broadcast by the TDRSS Augmentation Satellite System (TASS). The proposed innovation will combine the capability to receive TASS messages with SCP and the Goddard Enhanced Orbital Navigation System (GEONS) to provide precise PNT capabilities. SCP can track the L1 P(Y) chipping code-phase without an encryption module since it is codeless. Combining this capability with the ability to receive TASS messages in GEONS, on a suitable hardware platform will enable kinematic GPS capable of decimeter-level positioning in real-time. This effort determines how to best integrate these technologies, and to find a suitable host

Benefits: The proposed system can be utilized for any NASA mission in which GPS tracking is desired, and is especially useful for small satellites where SWaP concerns are critical. Because the system proposed integrates real time correction messages with a highly accurate codeless GPS navigation system which shares a heritage with JPL Blackjack technology, and utilizes GEONS as a Kalman Filter Navigation engine, deci-meter level positioning accuracies are possible. This high accuracy real time positioning enables future missions in which these are desirable goals. Due to the abilities of the unique receiver design proposed, it is possible to extend the sensor for scientific missions such as ionosphere profiling, and to extend navigation ability to degraded GPS or complex orbits such as those higher than GPS.

The proposed receiver system has significant applicability to DOD needs for positioning in orbits where conventional GPS is difficult, and can be extended to operate in cases where GPS is denied. The ability to produce highly accurate positions in a low cost, low swap, form factor, and in a software defined radio implementation has applications for operationally responsive space, in which a satellite must be assembled and launched quickly. Commercial applications include any application in which highly accurate positioning is required, in any orbital regime. This would include missions in which multiple satellites are required to operate in close proximity at known separations, and in systems in which the location of the satellite must be known to tag the data acquired.