초록 ▼

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 airbo

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.

대표청구항 ▼

1. An apparatus for determining a three-dimensional location of an airborne platform relative to a target area comprising:(a) a first antenna assembly positioned at the airborne platform and adapted to transmit energy downward toward a surface location directly beneath the airborne platform; (b) a s

1. An apparatus for determining a three-dimensional location of an airborne platform relative to a target area comprising:(a) a first antenna assembly positioned at the airborne platform and adapted to transmit energy downward toward a surface location directly beneath the airborne platform; (b) a second antenna assembly positioned at the airborne platform and adapted to transmit energy forwards toward the target area remote from the surface location; (c) a transmitter associated with the first and second antenna assemblies for transmitting signals toward the surface location and the target area; (d) a receiver coupled to the first and second antenna assemblies to receive and detect signals corresponding to the transmitted energy as reflected by the target area and the surface location; (e) a radar processor coupled to the receiver adapted to determine elevation measurements of the surface location beneath the airborne platform and three-dimensional heights of the target area from the detected signals, and to extract two-dimensional gray scale imagery of the target area from the detected signals; (f) geolocated, stored references of terrain heights of the surface location and target area; (g) a geolocated, stored reference of two-dimensional gray scale imagery of the target area, co-registered to the associated terrain height reference; (h) a height correlator for correlating the range between the platform and the surface location, and the three-dimensional height of the target area, to the stored reference of terrain heights; (i) an image correlator for correlating the extracted two-dimensional gray scale imagery of the target area to the stored reference of two-dimensional gray scale imagery; and (j) a navigational processor for determining 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.