A rho-theta relative position indicator for displaying separation and bearing with respect to a reference vehicle. From radar input parameters, the bearing of a lead or target vehicle is displayed as a pointer indication and separation is presented by the displacement of a second indicator along the bearing pointer axis, the combined display presenting location information for vehicle station keeping purposes.
An aircraft instrumentation having inherent self-checking features. Radar and barometric altitude information are displayed on the dial face of a single instrument. A cooperating dial and first pointer displays barometric altitude. A manually settable indicator "bug" cooperates with the dial to provide a presentation of the height of the airstrip relative to sea level. A second indicator "bug" of a different shape from the landing field bug is servo-driven from both radar and barometric altitude signal inputs to provide a presentation of aircraft altitude relative to the terrain beneath the aircraft. The angle between the barometric altitude pointer and servoed radar altitude "bug," measured counterclockwise, constitutes the distance of the aircraft above the airstrip or other terrain which the aircraft is passing over. Upon touchdown both "bugs" should be in exact coincidence, thereby serving as a self-check upon accuracy of the instrumentation.
