Abstract: A semiconductor laser pulse compression radar system utilizes a semiconductor laser source 16 for generating light for transmission towards a target 27. A modulator 15 pulses and modulates the light according to a preselected code, and a transmitter telescope 18 launches the light. Portions of the pulsed light reflected by the target 27 are gathered by a receiver telescope 28 and are converted to electrical current pulses by an avalanche photodiode 30. The pulses of electrical current are demodulated by demodulator 31, which includes a pulse compression filter 35 which has the conjugate time-frequency characteristic of the modulator. A display/counter 36 displays the range of the target from the system.