High-Speed, SAD Based Wavefront Sensor Architecture Implementation on FPGA
Wavefront aberrations caused by turbulent or rapidly changing media can considerably degrade the performance of an imaging system. To dynamically compensate these wavefront distortions adaptive optics is applied. We developed an affordable adaptive optic system which combines CMOS sensor and Liquid Crystal on Silicon (LCOS) display technology with the Field Programmable Gate Arrays (FPGA) devices parallel computing capabilities. A high-speed, accurate wavefront sensor is an elemental part of an adaptive optic system. In the paper, an efficient FPGA implementation of the Sum of Absolute Differences (SAD) algorithm, which accomplishes the correlation-based wavefront sensing, is introduced. This architecture was implemented on a Spartan-3 FPGA which is capable of real-time (>500fps) measuring the incoming wavefront.
sad wavefront sensor fpga real-time image processing