METHODS AND SYSTEMS FOR ESTIMATING THE ORIENTATION OF AN OBJECT

The system receives position information in both an internal coordinate frame and an external coordinate frame. The system uses a comparison of position information in these frames to determine orientation information. The system determines one or more orientation hypotheses, and analyzes the position information based on these hypotheses. The system may include on-board accelerometers, gyroscopes, or both that provide the measurements in the internal coordinate frame. These measurements may be integrated or otherwise processed to determine position, velocity, or both. Measurements in the external frame are provided by GPS sensors or other positioning systems. Position information is transformed to a common coordinate frame, and an error metric is determined. Based on the error metric, the system estimates a likelihood metric for each hypothesis, and determines a. resulting hypothesis based on the maximum likelihood or a combination of likelihoods.