A match/merge technique for 121.5/243 MHz beacons in theCOSPAS-SARSAT system

The COSPAS-SARSAT Mission Control Center (MCC) matches and merges estimates of position and frequency of 121.5/243 MHz distress beacons received from various ground stations and satellites. The matching and merging are done sequentially as the estimates are received, and merges are not reversed once sent out to search-and-rescue forces. A sequential, irreversible match/merge algorithm is derived based on the ratio of probabilities of the same beacon/different beacon hypotheses, and it is tested using data received at the United States MCC. The total number of mismatches based on tests for stability, correctness, and completeness was less than 0.5% when the match parameters were properly selected. The selected match parameters themselves were consistent with previously published results