Fig. 2.

Method for implementing (a) 1-D and (b) 2-D convolutions in the azimuth-elevation plane. In each case, the pre-computed field for a single piston is stored in global memory as illustrated. To reduce the number of accesses to global memory, which is the major bottleneck in the calculation, a block equal to the number of threads used (e.g. 1×8 or 8×8) and padded depending on the array size is copied from global memory to shared memory. The result for this block is then written to global memory. The * indicates the convolution operator.