GPS-translator processing system for ERIS

The author describes the requirements, design features, and capabilities of a Global Positioning System (GPS) based on the translator processing system (TPS) being procured for a tracking application for the US Army Strategic Defense Command´s (USASCD) exoatmospheric reentry vehicle interceptor subsystem (ERIS) project. The TPS provides the real-time position and velocity information for the target and the interceptor vehicles of the ERIS test project. To accomplish this, vehicle-mounted translators provide GPS C/A L-band to S-band signal conversion and retransmit to a TPS on the ground. The TPS measurements consist of pseudorange sums and pseudorange-rate sums to which differential GPS corrections are applied with the help of a GPS reference receiver. Two Kalman filters, dynamic and ballistic, are designed to satisfy differing accuracy requirements for the target and the interceptor