Radio location system with correction of propagation anomalies - using four transmitters and comparing extracted data with stored data to obtain correction criteria

摘要

The position location or navigation system has the transmitter positioned at the corners of a square and transmitting two different modulation frequencies, with the diagonally opposite transmitters coherently transmitting the same modulation frequency. At the location point the received signals are combined and four phases or propagation times extracted, to obtain conjugated phases whose intersection point defines the location point. The extracted measured data is compared with stored or calculated data to obtain the criteria for correction of the propagation anomaly and reflection errors.