The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 25, 1997
Filed:
Jun. 07, 1995
Mark Nichols, Sunnyvale, CA (US);
Kenneth W McBride, Los Altos, CA (US);
Ian Viney, St. Martins, NZ;
Arthur Taylor, Basingstoke, GB;
Richard Jackson, St. Albans, NZ;
John F Schipper, Palo Alto, CA (US);
Trimble Navigation, Sunnyvale, CA (US);
Abstract
A system for selecting an optimal transformation T(G2;G1) between a first ellipsoid E1 (e.g., WGS 84) in a first global coordinate system G1, relative to which the survey measurements are made, and a second ellipsoid E2 in a second global coordinate system G2. A set of location coordinates (x'.sub.m,2, y'.sub.m,2,z'.sub.m,2) for M previously-surveyed locations, numbered m=1, . . . , M, and a set of location coordinates (x'.sub.n,1, y'.sub.n,1,z'.sub.n,1) for N presently-surveyed locations, numbered n=1, . . . , N (M.ltoreq.N) are provided, where the first M presently-surveyed locations coincide with the M previously-surveyed locations. The transformation is chosen so that the images of the location coordinates (x'.sub.n,1,y'.sub.n,1, z'.sub.n,1) for n=1, . . . , M under T(G2;G1) are as close as possible to the corresponding location coordinates (x'.sub.m,2,y'.sub.m,2, z'.sub.m,2) for m=1, . . . , M. Given an ellipsoid and a selected survey plane .tau.0 that is tangent to the ellipsoid at a selected location, a set of selected locations can be surveyed with reference to the ellipsoid, and the location coordinates of each such surveyed location can be mapped into a corresponding 'survey location,' defined by reference to a local coordinate system that uses the survey plane .tau.0 as its base. These transformations and projections are determined and optimized in real time, while a surveyor is measuring the presently-surveyed locations in the field. The instruments used for surveying may be part of a location determination system, such as a Global Positioning System, a Global Orbiting Navigational Satellite System or Loran.