Study On Methods Of Array Errors Calibration And Its Implementation

The conventional high-resolution direction-of-arrival (DOA) estimation algorithms are based on the ideal steering vector in the presence of white Gaussian noise, i.e.There are no array errors, and the background noise is white Gaussian noise with known statistical properties. However, in practical applications, array errors are inevitable due to the array antenna craft or the circumstance around the array and so on.Consequently, DOA estimation in the presence of array errors is a research focus in array signal processing.In this thesis, the methods for DOA estimation in the presence of array errors are discussed.The conventional methods for array gain and phase uncertainties calibration require that the sources are impinging on the array with known locations. While the global convergence of auto-calibration based on iterative approach can't be guaranteed. Additionally, the DOAs and phase uncertainties are not independently identifiable for unifrom linear array. In this thesis, a method for array gain and phase uncertainties calibration with instrumental sources is presented. By using a single signal source (a calibration source or an object signal )without exact knowledge of its direction of arrival(DOA )and rotating the sensor array twice ,this method can precisely estimate the sensor gain,phase and position factors,and the array manifold in the presence of combined errors.Simultaneously,the DOA of the signal source can be estimated.Because the method is not an interactive method and spectral peak search is not required.Moreover,it can produce an high estimation precision.Simulational and experimental results show the mehod is effective.To resolve the array errors problem in a digital multi-beamformer project,a channel mismatch calibration algorithm was implemented by DSP .Testing results approved the improvement on the behavior of digital multi-beamformer.