Patent ID: 7978128
Filing Date: 2011-07-12
Classification: G01C,G01S

Abstract:
1. A land-based survey system, comprising: a vision positioning system configured to capture image data representing a sequence of images, said sequence of images including a plurality of non-common images of each of at least two different spaced apart fixed objects, said image data including known distance information; a processor configured to use said image data to derive position information for said vision positioning system based upon differences between images in said sequence of images, said differences being derived from said image data obtained from each of said spaced apart fixed objects; a position measurement system associated with said vision positioning system and configured continuously to obtain position information for said position measurement system that is based upon a known reference point and is subject to the accumulation of errors; and a computer configured to use said position information derived from said vision positioning system to reduce accumulated errors of said position measurement system.