An error analysis of GPS compass

In this paper, analytical error characteristics of GPS compass which determines heading and elevation of the vehicle using carrier phase measurements from two antennas is given. The derived result gives clear analysis of error statistics on attitude determination using GPS carrier phase measurement. It shows the accuracy of measured attitude relies on satellite geometry, performance of receiver, baseline length, baseline configuration and nominal attitude of vehicle. It is also shown that to obtain more precise heading, longer baseline along the vehicle is preferred and the accuracy of heading is always better than that of elevation since the vertical measurement uncertainty caused by geometry of satellites affects only on that of elevation. These results can be applied to basic directions for attitude determination: to what direction should the baseline be located to minimize the error, which satellites should be selected to minimize the error. These must be important and useful pre-information in attitude determination problem. An application to real data shows that the predicted error by the proposed method coincides with that of experiments