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.