Abstract: This invention allows personnel located on two different structures, such as two ships, to continually monitor the separation distance between the two structures, with all of the necessary equipment being located on only one of the structures. This is accomplished using a laser range finder, or other range sensor, to continually measure separation distance and send it electronically to various displays. The displays are positioned and sized such that all involved personnel can view the continually updating separation distances. The invention incorporates displays large enough to be viewed ship-to-ship in direct sunlight, in addition to smaller displays. The displays are dimmable or backlit for night viewing and include a safety feature that turns them off when communication is lost with any range sensor. A strobe on the display helps personnel find where the display has been positioned, such as on a ships gunwale or hand railing.

Abstract: A speed and/or position determining device for determining the speed or position of a target object includes a head-up display for simultaneously viewing both the target object and an image of information regarding the target object. An optical projection system for projecting the information image from a light emitting display to a combining sight of the head-up display passes along a short straight optical axis between the light emitting display and the combining sight. The device may also incorporate a novel method for determining the length of a time period that elapses between the time that a radiation emitter emits a pulse of radiation and the time a reflected portion of the emitted pulse of radiation is received back at the device. The novel method makes use of one or more electronic delay modules having a plurality of tap lines. An electronic state of each of the tap lines changes as a signal input to the delay module propagates through the delay module.