Calibrating an Array with Scan Dependent Errors Using a Sparse Grid

Today most arrays have a very high mechanical and electrical accuracy. Our aim is to allow for larger errors (low manufacturing cost), while keeping the calibration grid sparse (low calibration cost). To be able to handle the imperfections causing scan dependent errors (like position errors), we suggest a new array receive calibration method based on local models. The results show that our method performs much better than linear interpolation or global (direction independent) calibration regarding direction of arrival estimation using MUSIC for arrays with large position errors. In beamforming for e.g. communication, however, the global calibration performs better (lower side lobes) since it is optimized for the whole calibration region, while the local calibration is optimized for one direction.