A positioning method and realization on single satellites in different orbits using TDOA

The main geolocation technology currently used in COSPAS-SARSAT system is TDOA/FDOA or three-star TDOA, the principle is to determine the location of the signal source by using the difference in arrival time and frequency of the wireless signal between different receivers. Therefore, ground monitoring stations need to be equipped with more than two antenna receiving stations, and multiple satellites should be able to simultaneously relay the distress signal from the target source in order to achieve the geolocation function. However, when the ground receiving system has only one antenna receiving station, or the target source is in a heavily obscured environment, the ground side is unable to receive the forwarded signals from multiple satellites at the same time, which will make it impossible to locate. To address these problems, in this paper, a time-sharing single satellite geolocations method based on different orbits is proposed for the first time. This method uses one or several low-earth orbit satellites (LEO) and medium-earth orbit satellites (MEO) in the visible area, and the receiving station only needs one pair of receiving antennas to complete the positioning. It can effectively compensate for the shortcomings of the traditional TDOA using the same moment and have better positioning accuracy compared with the single satellite in the same orbit. Due to the limited experimental conditions, this paper tests the navigation satellite using different orbit time-sharing single satellite geolocations, and proves that the positioning method has high positioning accuracy and has certain promotion and application value.