A detector system within a lidar receiver is configured to compensate for range walk error by detecting both the rising edge and the falling edge of a received light pulse as the envelope of the received light pulse passes through a particular detection (magnitude) threshold. Detection circuitry within the detector system then determines the center of the received light pulse as the point equidistant in time between the detected rising and falling edges of the received light pulse, and uses the time associated with the center of the received light pulse to determine the range to the target from which the scattered light pulse was received.