Multiaperture echo signals collected by distributed array sar can be reconstructed to realize High-Resolution and Wide-Swath (HRWS) imaging. To achieve the HRWS imaging of distributedsar, an advanced Azimuth Multi-Ap...
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ISBN:
(纸本)9798350360332;9798350360325
Multiaperture echo signals collected by distributed array sar can be reconstructed to realize High-Resolution and Wide-Swath (HRWS) imaging. To achieve the HRWS imaging of distributedsar, an advanced Azimuth Multi-Aperture Reconstruction (AMAR) method is put forward for the first time. First, to eliminate the trajectory offset of distributedsar, the first-order baseline deviation, second-order baseline deviation and azimuth space variation error are compensated in turn for the calibrated and undersampled echo signals, and the echoes containing distorted azimuth ambiguity can be obtained. Second, the distortion of ambiguity is corrected by range decompression, anti-migration correction, etc. Finally, the echoes satisfying the Nyquist theorem are derived by the AMAR of Train formation, and the bistatic sar imaging is performed. In addition, some simulations are conducted to evaluate the performance of the proposed method, and the results demonstrate that the method can achieve AMAR and HRWS imaging of distributed array sar.
distributedarray synthetic aperture radar (DAsar), in which multiple distributed antennas are mounted on a crosstrack, has applications that include multibaseline interferometry, multiple-input multiple-output sar, a...
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distributedarray synthetic aperture radar (DAsar), in which multiple distributed antennas are mounted on a crosstrack, has applications that include multibaseline interferometry, multiple-input multiple-output sar, and tomography. However, this flexible imaging geometry requires accurate measurement of the movements of each antenna. High-precision navigation systems are commonly used, but configuring a separate navigational system for each antenna is challenging and costly. In this study, the authors proposed a novel motion compensation scheme for DAsar that combines inteferograms and inertial measurement. The authors fabricated a rigid baseline (RB) and multiple flexible baseline (FB) configuration, fitted with a large and accurate position and orientation system and with multiple smaller, low-precision inertial navigation systems (INS) for motion measurement. The authors introduced a new robust algorithm based on a function relating RB and FB interferometry, and used this to estimate the relative movements. Finally, a Kalman filter was designed to integrate the results of databased estimation and inertial measurement. This combined the strengths of data estimation for slow movement and inertial measurement for fast movement. The results of both simulations and airborne experiments confirmed the success of this novel approach in allowing a small INS to be used for motion compensation in DAsar applications.
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