A laser ranging system comprising a passively, Q-switched laser that emits a series of output pulses to form an output beam is described. A time interval between successive output pulses in the series of output pulses varies to form a distinctive sequence of output pulses. The laser ranging system further comprises a detector and a processor configured to determine a distance to the target based on a time interval between an emitted output pulse in the series of output pulses and a return reflected signal received by the detector.