Roman CGI testbed HOWFSC modeling and validation

Optical diffraction and wavefront sensing and control (WFSC) models validated against the high-fidelity Roman Space Telescope Coronagraph Instrument (CGI) testbed play a key role in mask design selection and the verification of many requirements that cannot be accomplished until the observatory is in orbit. We have been steadily improving our model fidelity for the as-built CGI testbed system. We demonstrate recently good agreement between measurements and model predictions while validating the Hybrid Lyot Coronagraph’s (HLC) performance using the in-orbit high order wavefront sensing and control (HOWFSC) operational scenario. We present modeling and testbed validation results that explain the reason why many testbed WFSC iterations were needed for HLC in the past. A new, direct application of model-generated initial deformable mirror (DM) voltage pattern has since been successfully demonstrated on the testbed with significant speed and performance improvement. This opens up new model-based initial DM pattern WFSC approaches for CGI. This can greatly reduce flight risk from potentially insufficient ground DM pattern generation due to schedule or cost constraints or from unexpected post-delivery changes. This work was performed at the Jet Propulsion Laboratory, California Institute of Technology under contract to NASA.