Precision all-weather target location system

Abstract

An apparatus to determine the three-dimensional location of an airborne platform relative to a target area using two separate antenna assemblies positioned on the airborne platform. The first antenna assembly is adapted to transmit energy downward toward a surface location directly beneath the airborne platform, while the second antenna assembly is adapted to transmit energy forward towards the target area remote from the surface location. A single transmitter is associated with both of the antenna assemblies for transmitting signals toward the surface location and the target area. A receiver coupled to the antenna assemblies receives and detects the signals corresponding to the transmitted energy as reflected by the target area and the surface location. A radar processor is coupled to the receiver and is adapted to determine the range between the airborne platform and the surface location and determine the three-dimensional height of the target area from the detected signals. The radar processor also extracts two-dimensional gray scale imagery of the target area from the detected signals. The apparatus also incorporates three geolocated stored references, one of terrain heights of the surface location and target area, one of the intensity image of the surface location, and the third of two-dimensional gray scale imagery of the target area. A height correlator compares the elevation measurements produced by the both the downward and forward looking platform sensors to the stored reference of terrain heights. The intensity of the radar return is also matched with a stored reference of intensities of the surface area. An image correlator for matching the extracted gray scale imagery of the target area to the stored reference of gray scale imagery is provided. A navigational processor then determines the three-dimensional location of the platform relative to the target area based on the correlation results of the height correlator and the image correlator.

Dependencies are inferred from the claim text.