Abstract: A system for measuring the position of an asset is provided. The system includes a first plurality of global positioning system (GPS) sensors arranged on a first asset, and a reference position source arranged on the first asset. One or more computer processors is provided in communication with a memory and is configured to measure position data associated with the first asset from the outputs of the first plurality of GPS sensors, and calculate a measurement offset between the measured position data associated with the first asset and position data obtained from the reference position source. From these measurements, position data measurements obtained from the plurality of GPS sensors of the first asset may be corrected using the calculated measurement offset. Likewise, position data measurements obtained from a plurality of GPS sensors of a second asset, located remotely from the first asset, are also corrected using the calculated measurement offset.

Abstract: Targets are sensed by a first sensor in a first coordinate system and by a second sensor in a second coordinate system. Gridlock or congruence between the coordinate systems is achieved by sensing at least four targets with both sensors. Pseudomeasurements are generated in both local and external coordinate systems by taking the differences between a first target location and each of second, third, and fourth target locations. The pseudomeasurements are filtered in corresponding pairs, to thereby generate an estimated rotation matrix between the local and external coordinate systems. The estimated rotation matrix is applied to the local coordinate system. The target locations in the rotated local and external coordinate systems are filtered in corresponding pairs to generate an estimated translation vector. The rotation and translation are applied to the local coordinate system to bring it into congruence with the external coordinate system.