here a klystron amplifier 13 and pulse modulator 14 pulse modulator 14 in response to signals supplied thereto via line xmt from timing and control unit 15 the details of which will be described in connection with fig3 produces a train of pulses of radio frequency energy at a desired prf here 1 200 mhz each one of the pulses in the train of transmitted pulses is reflected by various objects not shown which are disposed over various ranges from the antenna 11 a portion of the reflected energy produced in response to each transmitted pulse is received by antenna 11 the time at which a portion of such energy is received relative to the time at which the transmitted pulse associated therewith is transmitted corresponds to the range of the object causing such portion of the received energy the energy received by antenna 11 passes through circulator 12 the signal at the output of circulator 12 is heterodyned in a conventional manner in mixer 17 with a signal produced by a stable local oscillator stalo 18 the signal produced by stalo 18 is heterodyned with a signal produced by a coherent oscillator coho 19 in a mixer 20 to produce the train of transmitted pulses after amplification by the klystron amplifier 13 in a conventional manner the signal produced at the output of mixer 17 is passed through an if amplifier 21 to a quadrature phase detector 22 as indicated quadrature phase detector 22 responds in a conventional manner to thereby provide in phase and quadrature bipolar video signals such signals being separated into in phase and quadrature channels i q respectively the relationship between.