Bulk-FFBP: Fast Factorized Back-projection Algorithm Based on Range Bulk Processing

Block Fast Factorized Back-Projection (Block-FFBP) algorithm adopts a subaperture synthesis approach to reduce the computing complexity of the conventional BP algorithm, and partitions the echo data into blocks in range to avoid the complicated transforms between polar and Cartesian coordinates. However, Block- FFBP results in a range span vibration of the data blocks, and Block-FFBP needs an extra data length associated with the interpolation kernel. That gives rise to the inefficiency of the memory, and furthermore the degradation of the imaging speed. A range Bulk processing based FFBP (Bulk-FFBP) algorithm is proposed in this paper. It is implemented in two ways. One is based on a series of range pivots, and the other one is of no pivots. The outperformance of Bulk-FFBP relative to Block-FFBP is verified through simulations in error analysis, imaging evaluation and computing efficiency test.