PSR Min Range Factors RNAV
In contrast to maximum range, there is only really one determining factor when it comes to minimum range. The radar will transmit for a period, then stop transmitting and listen for replies. The problem for reflections from objects that are very close to the radar is that, if the radar is still transmitting, then it cannot (by design) hear the replies coming back from that object. Put another way, the radar has to shut its mouth and open its ears in time to hear the returning pulse from the nearby object. The amount of time the radar transmits for is called the pulse length or width, and this is the factor that determines minimum range.