基于时延估计的分裂阵时域波束形成技术

大孔径拖曳线列阵受舰艇横向机动、洋流影响和水动力影响时会产生一定的阵形畸变，阵形畸变使得波束形成时阵列流型失配，进而降低了目标方位分辨率和阵处理的增益。在无法进行阵形估计时，基于时延估计的分裂阵时域波束形成技术将大孔径拖曳线阵分为左右两个子阵分别做波束形成，通过加权广义相关时延估计算法估算对应波束的时延差，再依据估算时延差对左右两个波束进行延时求和得到最终的波束信号。仿真和海试数据证明，相对于全阵直接做波束形成的方法，基于时延估计的分裂阵的时域波束形成技术有效提高了目标方位分辨率和阵处理的增益。

Split array time domain beamforming technology based on time delay estimation

The large aperture towed linear array will produce certain array distortion when it is affected by ship lateral maneuver, ocean current and hydrodynamic forces. Array distortion makes array flow pattern mismatch in beamforming, which reduces beam resolution and array gain. When we can not estimate the formation, split array time-domain beamforming technology that based on time delay estimation divides large aperture towed linear array into left and right subarrays for beamforming respectively. The delay difference of the corresponding beam is estimated by the maximum likelihood time-delay estimation algorithm. Then, the left and right beam signals are delayed according to the estimated delay difference, and the delayed beam signals are added to get the final beam signal. Simulation and sea trial data show that the time domain beamforming technology based on time delay estimation can effectively improve the target arzimuth resolution and signal gain compared with the whole array direct beamforming method.