Effect of target surface orientation on the range precision of laser detection and ranging systems

Airborne laser detection and ranging (LADAR) systems are used for applications such as three-dimensional imaging, topographic mapping, and target recognition. Typical systems transmit laser beams through apertures that are a few inches wide and use pulses that are roughly a nanosecond in duration. If the pulse reflects off a target that is tilted with respect to the LADAR's line-of-sight, then the reflection process will elongate the received signal as compared to the transmitted pulse. If the range is more than a few kilometers and the target is tilted more than about forty-five degrees, the increase in the width of the received pulse produces a signifcant drop in range precision as compared to when the target is perpendicular to the line-of-sight.