Abstract: An apparatus and method for the measurement of water depth between a water surface and water bottom and adapted for mounting on an aircraft flying above the water surface. The apparatus includes a transmitter and a receiver of laser light. The laser light is reflected from a secondary mirror to a primary mirror and to the water where it is subsequently reflected both from the water surface and the water bottom. The primary mirror then collects these reflections where they are then reflected to a receiver to be processed for subsequent analysis. So as to scan across the water surface the primary mirror is oscillated around a major axis generally transverse to the aircraft flying direction as well as parallel to the aircraft direction to compensate for the aircraft movement, the reflections recorded in a temporal fashion.

Abstract: An Laser Airborne Depth Sounder (LADS) system for the measurement of water depth is disclosed, the system includes a transmitter and a receiver of laser light having at least two wavelengths so as to receive a first reflection from a water surface and a second reflection from a water bottom an a rotating mirror which directs the laser light to the water and receives the second reflection of the laser light from the water bottom and directs the second reflection to the receiver, where the receiver includes an optical shutter (76) adapted for selectively allowing the passage of the second reflection laser light therethrough. The shutter (76) may include a LCD matrix or mechanical light blocking elements. The LCD matrix may be arranged in a central circle (82), an inner ring (80), and an outer ring (78).

Abstract: A Laser Airborne Depth Sounder (LADS) system for the measurement of water depth is disclosed, the system includes a transmitter and a receiver of laser light having at least two wavelengths so as to receive a first reflection from a water surface and a second reflection from a water bottom, and a mirror (32) adapted to reflect the second reflection laser light and rotate around a major axis (34) and minor axis (36) where the rotation of the mirror (32) around the minor axis (36) is provided by a piezo electric actuator (68). The piezo electric actuator (68) drives the mirror (32) around the minor axis (36) through a mechanical level (72).