海洋4A散射计幅相校正算法FPGA优化实现

FPGA optimization implementation of amplitude and phase correction algorithm for ocean 4A scatterometer

海洋4A散射计将是世界上首个采用相控阵数字波束合成体制的星载微波散射计。其中,相控阵散射计高精度测量的实现依赖于散射计系统中各通道的一致性,因此需要实时对各通道的幅度和相位进行校正,以确保阵列能够正确地合成所需的波束。针对此问题,提出了一种相控阵散射计通道幅相实时校正算法,所提算法采用现场可编程门阵列(field-programmable gate array,FPGA)实现,利用FPGA的并行处理能力和高速性能,对接收到的信号进行实时处理,实现了通道的幅度和相位校准。仿真、FPGA硬件调试以及实测数据分析表明,所提算法能够有效地对通道进行幅相校正,其校正的幅度和相位平均误差小于1%;所提算法提高了数字波束合成的性能,为相控阵散射计的高精度测量提供了可行性。

The Ocean 4A scatterometer is the world’s first spaceborne microwave scatterometer employing a phased-array digital beamforming system.Achieving high-precision measurements in phased-array scatterometers relies on the consistency of individual channels within the system.Therefore,it necessitates real-time correction of the amplitude and phase of each channel to ensure the array accurately synthesizes the required beams.This paper presents a real-time amplitude and phase correction algorithm for phased-array scatterometer channels.The proposed algorithm is implemented using field-programmable gate array(FPGA),capitalizing on FPGA’s parallel processing capabilities and high-speed performance to process received signals in real-time,thereby achieving amplitude and phase calibration for the channels.Simulations,FPGA hardware implementation,and analysis of measured data show that the proposed algorithm effectively corrects channel’s amplitudes and phases,with an average error of less than 1%.The proposed algorithm enhances the synthetic performance of digital beamforming,demonstrating the feasibility of high-precision measurements in phased-array scatterometers.