US Patent 7355513 Ultra-reliable personnel position locating system

A survivor locator system allows for the detection of the location for a person who is lost and requires recovery and extraction from their current environment. By using a phase matched antenna set, a GPS receiver, and a handheld simplified beacon-equipped survival transponder, an estimated distance and bearing data set can be retrieved. If this data set estimation is then fed through an error reduction filter, such as a Kalman filtering algorithm, continually refined location coordinates can be generated, leading the search and rescue crew members to the survivor. The survivor locator system and methods provide a handheld survival radio with reduced complexity.