Abstract: A novel timing control method is utilized in conjunction with an imaging lidar system of the type disclosed in U.S. Pat. No. 4,862,257. This novel timing control is employed in applications wherein the lidar system is mounted on an airborne platform. The timing control method of this invention completely eliminates the glint detector with associated signal conditioner used in the system of U.S. Pat. No. 4,862,257, and instead, relies upon a signal derived from the aircraft altimeter to continually provide platform altitude status. Since the entire system is under the control of a computer, the altimeter signal can be interpreted and used to adjust total delay so as to automatically track changing platform altitude. It is now possible to initiate all timing from the occurrence of the laser "lamp fire" signal. The total delay to camera "gate on" is now the "lamp-to-laser" delay, plus round trip platform altitude delay (computer from the altimeter signal), plus desired water depth delay, less system delays.