Abstract: A position reference sensor for a marine vessel comprises an optical assembly including a pulsed laser device for emitting laser light, a lens arrangement comprising a lenticular lens for producing a vertically fanned beam (18) of the laser light emitted by the pulsed laser device and a photodiode (32) comprising a plurality of photodetectors Rx, Ry, Rz for detecting laser light (28) that has been emitted by the pulsed laser device and reflected by a retro-reflective target (22) towards the photodiode (32). The level of reflected laser light incident upon each photodetector is individually detectable and the position reference sensor further comprises an actuator for varying the inclination of the optical assembly. The actuator is automatically controllable based on the level of reflected laser light incident upon each photodetector Rx, Ry, Rz.

Abstract: An active radar target includes several receive antennas and several transmit antennas that are arrangeable into pairs of antennas. Each pair includes a transmit and a receive antenna. At least one antenna in a pair is at a different height relative to at least one other antenna in a different pair of antennas.

Abstract: A position reference sensor for a marine vessel comprises an optical assembly including a pulsed laser device for emitting laser light, a lens arrangement comprising a lenticular lens for producing a vertically fanned beam (18) of the laser light emitted by the pulsed laser device and a photodiode (32) comprising a plurality of photodetectors Rx, Ry, Rz for detecting laser light (28) that has been emitted by the pulsed laser device and reflected by a retro-reflective target (22) towards the photodiode (32). The level of reflected laser light incident upon each photodetector is individually detectable and the position reference sensor further comprises an actuator for varying the inclination of the optical assembly. The actuator is automatically controllable based on the level of reflected laser light incident upon each photodetector Rx, Ry, Rz.