Xuehui He

Pattern synthesis with desired magnitude response for arbitrary arrays

A pattern synthesis with desired magnitude response based on the combination of genetic algorithm and convex optimization is proposed. The phase in mainlobe is used as the optimization variables for genetic algorithm, and the fitness function is constructed with the desired magnitude of mainlobe. The optimal fitness degree for the corresponding individual can be obtained through solving the fitness function with the convex optimization, which improves the algorithm search performance with great efficiency. The optimization design in phase makes the synthesis result has no relation to the array reference point and the proposed algorithm is suit for the array synthesis with arbitrary element positions. The validity of method is confirmed by the result of the simulate data.

An Array Pattern Synthesis Method with the Constraint of Weight Amplitude Dynamic Range

An improved pattern synthesis algorithm based on optimization theory is proposed. The non-convex problem of array pattern synthesis with a dynamic range constraint in amplitude is converted to two convex formulations for optimization, and the amplitude of the optimal weight is confined to a certain dynamic range. The proposed method provides the optimal tradeoff among the mainlobe pattern, the sidelobe level and the dynamic range in weight amplitude, which has many advantages, such as flexible design, high accuracy and good convergence. The validity of method is demonstrated by the result of the simulate data.

Optimizing and Implementing the Fast Algorithm for Real Time SAR Imaging

A fast correlation algorithm in SAR imaging is presented to lower down the computation burden of range compression and azimuth focusing processing. It is based on the decomposition method of DFT. In order to minimize the computation amount, the relationship of number of padding zeroes and the decomposition scheme to computation complexity is investigated, which is dependent on the number of correlation filter coefficient taps. Then for different numbers of correlation filter coefficient taps, the number of padding zeroes and decomposition scheme are optimized. This algorithm is superior in computational efficiency compared with other algorithms. It is applied to real time SAR imaging and proved to be effective in computation