Accuracy improvement for GNSS -based compass

Abstract

Abstract To calculate relative position of two navigation antennas with a relatively short baseline phase measurements are commonly used. This approach is associated with technical difficulties related to the synchronization of receivers and resolution of phase ambiguities. Double phase differences of eliminate these errors and therefore allow to calculate the azimuth with better accuracy. Proposed algorithm for phase ambiguities resolution consists of three steps: applying double phase difference model insensitive to full phase due to the usage of cosine function, secondly using differential evolution method to fit model to observation by varying orientation angles and finally computing phase ambiguities from roughly estimated angles. To reduce the phase centre shift influence on azimuth computation error, the correction function depending on navigation signal arrival angles was introduced. To find its numerical values, the experiment with rigidly fixed antennas was carried out. Its idea was to take into account the relative movement of navigation satellites in fixed antenna system. Development of a multi-antenna navigation receiver with an additional channel for calculating phase ambiguities is described.