Local surface reconstruction of orbital objects

Conventional vision systems designed to reconstruct the surfaces of objects generally handle only diffuse objects or objects with a minimal amount of specularity. The presence of specular reflections produced by highly specular surfaces confuse traditional vision systems and may mask the true location of an object and lead to incorrect measurements. This article describes the development of a fixed vision system which can recover the local surface structure of highly specular objects. The system utilizes a commercial trinocular stereo vision system and a low-power twodimensional illuminant. The local surface structure of an object is obtained by projecting coded light patterns onto the object. As many objects are neither fully specular nor fully diffuse, the statistical method of mixture models is used to divide an object into specular and diffuse components in order to recover local surface structure from both specular and diffuse regions. The system was originally designed to assist in the insitu repair and maintenance of man-made orbital objects. One of the key challenges facing computer vision systems used in space is the presence of specular surfaces on virtually all man-made orbital objects. Because it was designed to be used in outer space, the system was designed to operate without traditional high-powered illuminants, such as laser beams, whose radiation can interfere with sensitive space instruments. While the system was designed to operate in outer space, it offers many other practical non-space applications.