Lock-on-after launch missile guidance system using three dimensional scene reconstruction

DETAILED DESCRIPTION In accordance with the present invention, rather than using a two dimensional description of the target (template) to match a two dimensional realization of the target (the sensor image), a three dimensional description of the target area is generated using the sequence of two dimensional sensor images combined with relative movement of the missile.
This 3D description is matched to a 3D model of the target area or a 3D description of the target scene is projected into the 2D reconnaissance image and registers in 2D.
In addition, rather than manually modeling only a few unique aspects of the target, the entire target area is automatically modeled.
Also, rather than relying upon prediction of a few required contrasts, the invention merely requires location of a sufficient number of object outlines to be unique to the target.
Furthermore, rather than having one preset range at which acquisition must take place, acquisition is a continuous process in which the final aimpoint decision can be easily delayed until a high enough level of registration confidence is achieved.
The above is accomplished in conjunction with a 3D.
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-- LOAL algorithm composed of two parts, one part being 3D.
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-- Prebriefing (the target area processing that takes place before the missile is launched) and 3D.
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-- LOAL which occurs after the missile is in flight.
In conjunction with 3D.
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-- Prebriefing, the algorithm may use several different types of information to acquire aimpoints.
These types of information are, in order of desirability, (1) facet based, (2) wire frame based prebrief and (3) recon-photo based prebrief.
In the case of facet based information, individual objects in the target area are described by 3D polygons (facets).
Therefore, the algorithm determines which object properties will be visible from any particular viewpoint and eliminates hidden lines from ever being considered in the matching process.
This type of information is usually available for "high value" targets.
An aimpoint and trackpoint are described as 3D points referenced to this set of 3D facets