Sensor Gain-Phase Errors Estimation Using Disjoint Sources in Unknown Directions

Sensor gain-phase error estimation is necessary for equipment using sensor array, such as radar, sonar, and mobile communication before they come into service. Due to this requirement, we propose an offline calibration algorithm for sensor gain-phase errors using two auxiliary sources, which appear independently of both space and time, named disjoint sources. The significant superiority of this algorithm lies in the use of calibration sources in unknown directions. First, based on the data covariance matrix, the sensor phase errors are obtained, and the relation between phase error matrix and array manifold is established. Second, the directions of two disjoint sources are obtained by the way of 2D search based on eigen-structure subspace method. Third, we provide two methods to realize the algorithm. The proposed algorithm performs independently of phase errors. Moreover, the accurate direction measurement of calibration sources is not necessary. Computer simulations are shown to verify the efficacy of the proposed algorithm.