Factors affecting the range of radar sets

IT is now well known that most of the radar sets used in the past war function by transmitting a pulse and measuring the time necessary for the signal to reach the target and the echo to return. Of particular interest is the problem of finding how much power must be transmitted so that the echo will be of sufficient strength to be detected satisfactorily by the radar receiver. When dealing with microwave equipment and the consequent line-of-sight transmission paths, the problem can be solved by geometric means.