Synthetic Aperture Radiometer Error Correction Method

Limited by the antenna physical aperture, the traditional milli-wave radiometer can’t get good development for it’s low spatial resolution. As a new array interferometric array milli-wave radiometric, milli-wave aperture synthesis radiometer (ASR) forms a large physical observation aperture by a thinned array of small-aperture antennas, which reduced the antenna size and weight, high resolution and can instantaneously imaging for the entire field of view (FOV) without scanning. So it can better meet the needs of practical application and has a strong application prospects.The basic imaging theory and the system structure of milli-wave aperture synthesis radiometer (ASR) is presented first, including one dimensional and two dimensional image inversion imaging theory. Three kind of classical ASR systems were presented. The systematic errors analysis and calibration methods are presented after knowing the structure of the system.In this thesis, two blind estimation algorithm were given to calibration the array gain/phase error under the array error model. Several ways of calibration array gain/phase error, mutual coupling, position error based on external auxiliary sources calibration the whole system error were present:(1) The external single auxiliary source. A calibration algorithm which estimates the gain/phase error by using a single auxiliary source with exact direction, high radiation intensity and the structural characteristics of array distortion model.(2) The external single auxiliary source based on antenna array rotation. A calibration algorithm which estimates the array gain/phase and position errors by using a single auxiliary source with exact direction, high radiation intensity and rotating the sensor array twice.(3) The external auxiliary sources. A calibration algorithm which estimates the array gain/phase and mutual coupling errors by combining with the covariance matrix of the target scene and the covariance matrix of the target scene with external sources, and the sparse of mutual coupling matrix.Finally, simulation verify and compare the performance of the proposed algorithms with traditional algorithms, and use it calibration the error inversion image.