Cost Effective One-Way Doppler Measurements Correction of NOAA Satellites Using GPS Dissemination

Kurzfassung

This paper describes a new low cost method implemented in Bremen university ground station for correcting Doppler measurements based on GPS techniques. The facilities of the tracking ground station to determine the one-way Doppler shift of the NOAA weather satellites are described. Using an open source GPS platform, frequency bias in the measurement and receiving devices was measured. The performance of the low cost instruments with antennas, rotor controller, receiver, frequency counter and open source GPS terminal will be explained. This station is a reassembly of the same ground station used previously in 1994 to support the BREM-SAT mission, with the addition of the GPS terminal in order to measure the reference oscillator’s error. Incorporating all the processed measurements, a corrected Doppler shift curve will result which differs from the original measured Doppler curve by the fact that the frequencies now are the absolute values. The results are compared with the expected nominal predictions. Finally, the least square algorithm was implemented for orbit determination using the uncorrected and corrected measurements.