Parallel-Computing Architecture for JWST Wavefront-Sensing Algorithms

Abstract : The James Webb Space Telescope (JWST) is the successor to the Hubble Space Telescope and will be NASA's premier observatory of the next decade. Image-based wavefront sensing (phase retrieval) is the primary method for ground testing and on-orbit commissioning. For ground tests at NASA's Goddard Space Flight Center (GSFC) and Johnson Space Center (JSC), near-real-time analysis is critical for ensuring that pass/fail criteria are met before completion of a specific test. To address this need we have developed a computational architecture for image processing and phase retrieval. Using commercially available off-the-shelf hardware and software, we have designed, implemented, and tested a solution for high-speed parallel computing. The architecture is a hybrid solution utilizing both CPUs and GPUs and exploiting the unique advantages of each. Discussions are presented of the architecture, performance, and current limitations.