Recursive Starlight and Bias Estimation for High-Contrast Imaging with an Extended Kalman Filter

Abstract

For imaging faint exoplanets and disks, a coronagraph-equipped observatory needs focal plane wavefront correction to recover high contrast. The most efficient correction methods iteratively estimate the stellar electric field and suppress it with active optics. The estimation requires several images from the science camera per iteration. To maximize the science yield, it is desirable both to have fast wavefront correction and to utilize all the correction images for science target detection. Exoplanets and disks are incoherent with their stars, so a nonlinear estimator is required to estimate both the incoherent intensity and the stellar electric field. Such techniques assume a high level of stability found only on space-based observatories and possibly ground-based telescopes with extreme adaptive optics. In this paper, we implement a nonlinear estimator, the iterated extended Kalman filter (IEKF), to enable fast wavefront correction and a recursive, nearly-optimal estimate of the incoherent light. In Princeton's High Contrast Imaging Laboratory we demonstrate that the IEKF allows wavefront correction at least as fast as with a Kalman filter and provides the most accurate detection of a faint companion. The nonlinear IEKF formalism allows us to pursue other strategies such as parameter estimation to improve wavefront correction.

30 pages, 14 figures

References in corpus (1)

• Recursive Starlight and Bias Estimation for High-Contrast Imaging with an Extended Kalman Filter

Cited by in corpus (13)

• Observing Exoplanets with High-Dispersion Coronagraphy. II. Demonstration of an Active Single-Mode Fiber Injection Unit
• Shaped Pupil Lyot Coronagraphs: High-Contrast Solutions for Restricted Focal Planes
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• Speckle suppression and companion detection using coherent differential imaging
• Active correction of aperture discontinuities - optimized stroke minimization II: optimization for future missions
• Active correction of aperture discontinuities - optimized stroke minimization I: a new adaptive interaction matrix algorithm
• Experimental validation of joint phase and amplitude wave-front sensing with coronagraphic phase diversity for high-contrast imaging
• Review of high-contrast imaging systems for current and future ground- and space-based telescopes I. Coronagraph design methods and optical performance metrics
• Demonstration of an electric field conjugation algorithm for improved starlight rejection through a single mode optical fiber
• High-Contrast Integral Field Spectrograph (HCIFS): multi-spectral wavefront control and reduced-dimensional system identification
• Fundamental limits to high-contrast wavefront control
• Capabilities of ACAD-OSM, an active method for the correction of aperture discontinuities
• Dark zone maintenance results for segmented aperture wavefront error drift in a high contrast space coronagraph