Integer ambiguity resolution for GPS based attitude determination system

The attitude of a vehicle can be precisely determined using GPS (Global Positioning System) carrier phase measurements from more than two antennas attached to the vehicle with properly applied efficient integer ambiguity resolution technique. Many methods utilizing the known baseline length as a constraint have been proposed to resolve integer ambiguity in real-time manner. Three-dimensional search space is reduced to two-dimensional search space with this constraint. But there exist still strong requirements for the fast integer ambiguity resolution, which uses single epoch measurement of longer baseline. In this paper, a new constraint from the geometry of multiple baselines is derived. With this new constraint, two-dimensional search space is further reduced to one-dimensional search space.