allows reflections from missile 30 to return to the receiver associated with the emitting transmitter before the next transmitter pulse is emitted this is true because the maximum distance range necessary may be on the order of 185 feet the synchronizer 28 may incorporate range gate functions to prohibit reception of range signals other than from desired ranges in the preferred embodiment of the invention the maximum range is limited to 185 feet and the range gates are programmed to step in increments of 1 4 foot time separation of the four r t unit pulses avoids the necessity for operating the units on different frequencies or otherwise identifying a particular return pulse with a given transmitted pulse the utilization of the range gate stepping system also avoids excessive extraneous noise in the system as a pulse is emitted from each one of the r t units 20 22 24 and 26 the synchronizer 28 starts a range counter the pulse signal is reflected 34 from the missile and received in the same r t unit where it is converted to a video signal each of these video signals is then fed to the synchronizer 28 and each is used to stop a range counter thereby creating a digital signal which is proportional to the range between the missile 30 and the target 10 an appropriate digital word is generated in synchronizer 28 incorporating this digital range and a digital code which serves to identify the particular r t unit and antenna from which the range data was derived referring to fig5 prf oscillator 60 generates a frequency of for example 1 6 megahertz this frequency.