The Rebuilding And Design Of Ground Station Of Cospas-Sarsat

The International Cospas-Sarsat (C/S) Programme provides accurate, timely, and reliable distress alert and location data to help search and rescue (SAR) authorities assist persons in distress. C/S System including satellites in low-altitude Earth orbit and geostationary Earth orbit, as well as the corresponding ground equipment, provides distress alerts to SAR services and inquiry service of the user registration information to the maritime, aviation and land users. This paper focuses on the rebuilding and design of three parts of C/S:the antenna unit, local user terminal (LUT) and the mission control center (MCC). So it will enhance the performance of new system in all aspects and provide more timely and accurate SAR service.As the first part of radio frequency receiving unit, antenna receives the satellite signal. The antenna designed in this paper has dual antenna structure with new technology, small volume, high precision of signal receiving to enhance the system performance of the technical feasibility. Dual antenna structure ensures the signal completely received and meet needs of receiving two satellites signal.LUT plays a key role, it not only controls the antenna, but also receives the downlink data using the Doppler effect for processing, sand send data to the mission control center for final positioning analysis. Therefore the local user terminal has an adaptive function, automaticlly tracks satellite according to the satellite schedule.With the processed message from LUT, MCC displays different types of distresses on the map different symbols, and generates a distress alarm message. At the same time, according to the data division plan of C/S, MCC will exchange the message with other MCC automaticlly. Locating timely, generating message accurately and rich function are very important in MCC design.After the complete of the parameter setting, software and hardware debugging, as well as the position and specific function testing, We have successfully finished a three days Commissioning test. The whole system has reached the requirements of the Cospas-Sarsat, and finally admitted into the network.