Simulating the GPS constellation for high fidelity operator training

This paper describes the development of the high fidelity GPS simulator Loral. The simulator will build upon existing ground system simulator software, and will take advantage of actual GPS spacecraft software developed by the satellite and payload manufacturers. Using multiprocessor computers, the system will simulate the entire satellite constellation to provide training in managing GPS worldwide navigation performance. At the same time, up to 4 complete satellite simulations can be run simultaneously to train in routine and anomalous operations of the satellites and satellite subsystems. Finally, all ground resources outside the walls of the RIGS are simulated. The simulator's user interface will allow instructors to easily input all types of anomalies to test the reaction of the students. The simulator will allow GPS operators to train individually, or as a unit, in handling true "day-in-the-life" scenarios prior to becoming certified. In addition, this paper discusses how the simulator will allow high fidelity testing of control system upgrades, reducing the need for operational resources during test. Finally, it discusses how the simulator can be adapted to support other less traditional applications.