Pipeline structure for real-time centroid calculation of Hartmann wavefront sensor with horizontal multi-channel pixel output

In this paper, a real-time pipeline centroid calculating structure based on programmable logic devices is designed for Hartmann wavefront sensor with horizontal multi-channel pixel output. The pipeline consists of modularized cells including multiplier groups, accumulation cells, dividers and corresponding control units. The structure is specially designed to deal with simultaneously output pixels which belong to two adjacent subapertures as well as those pixels belong to the same subaperture. When the number of output channels is 8 and pixels output at 80MHz clock frequency, centroid calculation latency in simulation is less than 0.5μs.