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Space coronagraphs are projected to detect exoplantes that are at least 1e10times dimmer than their host stars. Yet, the actual detection threshold dependson the instrument's wavefront stability and varies by an order of magnitudewith the choice of observation strategy and post-processing method. In thispaper the authors consider the performance of the previously introducedobservation strategy (dark hole maintenance) and post-processing algorithm(electric field order reduction) in the presence of various realistic effects.In particular, it will be shown that under some common assumptions, thetelescope's averaged pointing jitter translates into an additional light sourceincoherent with the residual light from the star (speckles), and that jitter"modes" can be identified in post-processing and distinguished from a planetsignal. We also show that the decrease in contrast due to drift of voltages indeformable mirror actuators can be mitigated by recursive estimation of theelectric field in the high-contrast region of the image (dark hole) usingElectric Field Conjugation (EFC). Moreover, this can be done even when themeasured intensity is broadband, as long as it is well approximated by anincoherent sum of monochromatic intensities. Finally, we assess the performanceof closed-loop vs. open-loop observation scenarios through a numericalsimulation of the Wide-Field Infra-Red Survey Telescope (WFIRST). Inparticular, we compare the post-processing factors of Angular DifferentialImaging (ADI) with and without Electric Field Order Reduction (EFOR), which weextended to account for possible telescope rolls and the presence of pointingjitter. For all observation parameters considered in this paper, close-loopdark hole maintenance resulted in significantly higher post-processingaccuracy.

On the Effects of Pointing Jitter, Actuators Drift, Telescope Rolls and  Broadband Detectors in Dark Hole Maintenance and Electric Field Order  Reduction