| Presently, the position and velocity of orbiting satellites are determined using measurements provided by ground radar stations (GRSs). The time it takes to route the measurements to the desired computer so that the position and velocity can be estimated can be as long as hours or even days. The position and velocity errors obtained with GRS measurements can be in the range of hundreds of kilometers. In addition, GRSS are usually not dedicated to the desired satellite. This thesis describes an alternative approach which utilizes the global positioning system (GPS) signals together with an eight-state Kalman filter to accurately determine a satellite's position and velocity in real time. A high-fidelity simulation was developed to demonstrate the eight-state Kalman filter performance. Results will show that by using the currently available GPS signal, position and velocity errors less than 100 m and 1 m/s can be achieved. |
