一种用于SAR成像的数据存储系统设计方法

A design of data storage system for SAR imaging

摘要:

针对合成孔径雷达(SAR)成像回波数据量巨大和存储器资源利用率偏低的问题，提出一种双倍数据速率动态随机存储器(DDR)的存储装置，并设计一种原位转置的存储方法。该方法首先比较雷达回波数据距离向和方位向的长度，通过预留出距离向和方位向中较长数据的单行或者单列所占用的存储空间来提高存储器读地址和写地址逻辑映射的灵活性，有效地实现了大数据量的片内转置操作，提高了双倍数据速率动态随机存储器(DDR)的资源利用率，并将分块子矩阵地址映射方法和跨页地址映射方法应用于原位转置中，有效地提高了SAR回波数据转置的访问效率。仿真实验结果表明，该数据存储系统在满足成像实时性的同时降低了一半的DDR存储器的用量，提高了DDR的资源利用率，降低了成本，目前已成功应用于多种模式的SAR成像处理中。

Abstract:

A Double Data Rate(DDR) Synchronous Dynamic Random Access Memory(SDRAM) combined with Quad Data Rate(QDR) Static Random Access Memory(SRAM) storage system is proposed to overcome the problem of huge amount of SAR imaging echo data. An in-place transposed storage method is designed for the system to improve the memory resource utilization. This method compares the length of the range and the azimuth of radar echo data firstly. It reserves some free space of the memory to improve the flexibility of the logical mapping of the read address and the write address of memory. The free space is the same as the storage space occupied by a single row or column of longer data in the range direction and the azimuth direction. It effectively realizes the on-chip transposition operation of a large amount of data, and saves the utilization amount of DDR. And the sub-block matrix address mapping method and cross-BANK address mapping method are applied to the in-place transposition, which effectively improves the access to the SAR echo data transposition. The experimental results show that the data storage system reduces the amount of DDR memory by half while meeting the real-time imaging requirement, improves the resource utilization of DDR, and cuts the cost. At present, it has been successfully applied to SAR imaging processing in multiple modes.