High-contrast Imaging from Space: Speckle Nulling in a Low Aberration Regime

Abstract

High-contrast imaging from space must overcome two major noise sources to successfully detect a terrestrial planet angularly close to its parent star: photon noise from diffracted star light, and speckle noise from star light scattered by instrumentally-generated wavefront perturbation. Coronagraphs tackle only the photon noise contribution by reducing diffracted star light at the location of a planet. Speckle noise should be addressed with adaptative-optics systems. Following the tracks of Malbet, Yu and Shao (1995), we develop in this paper two analytical methods for wavefront sensing and control that aims at creating dark holes, i.e. areas of the image plane cleared out of speckles, assuming an ideal coronagraph and small aberrations. The first method, speckle field nulling, is a fast FFT-based algorithm that requires the deformable-mirror influence functions to have identical shapes. The second method, speckle energy minimization, is more general and provides the optimal deformable mirror shape via matrix inversion. With a NxN deformable mirror, the size of matrix to be inverted is either N^2xN^2 in the general case, or only NxN if influence functions can be written as the tensor product of two one-dimensional functions. Moreover, speckle energy minimization makes it possible to trade off some of the dark hole area against an improved contrast. For both methods, complex wavefront aberrations (amplitude and phase) are measured using just three images taken with the science camera (no dedicated wavefront sensing channel is used), therefore there are no non-common path errors. We assess the theoretical performance of both methods with numerical simulations, and find that these speckle nulling techniques should be able to improve the contrast by several orders of magnitude.

31 pages, 8 figures, 1 table. Accepted for publication in ApJ (should appear in February 2006)

References in corpus (9)

• A Giant Planet Candidate near a Young Brown Dwarf
• Detection of Thermal Emission from an Extrasolar Planet
• Infrared radiation from an extrasolar planet
• Limits of Adaptive Optics for high contrast imaging
• Giant Planet Companion to 2MASSW J1207334-393254
• Evidence for a co-moving sub-stellar companion of GQ Lup
• Exoplanets imaging with a Phase-Induced Amplitude Apodization Coronagraph - I. Principle
• Pupil Mapping in 2-D for High-Contrast Imaging
• Imaging Earth-like planets with Extremely Large Telescopes

Cited by in corpus (87)

• Fundamental limitations of high contrast imaging set by small sample statistics
• Theoretical Limits on Extrasolar Terrestrial Planet Detection with Coronagraphs
• Spectral Evolution of an Earth-Like Planet
• PALM-3000: Exoplanet Adaptive Optics for the 5-meter Hale Telescope
• Optimal Dark Hole Generation via Two Deformable Mirrors with Stroke Minimization
• Review of small-angle coronagraphic techniques in the wake of ground-based second-generation adaptive optics systems
• Speckle noise and dynamic range in coronagraphic images
• Observing Exoplanets with High-Dispersion Coronagraphy. II. Demonstration of an Active Single-Mode Fiber Injection Unit
• On-sky speckle nulling demonstration at small angular separation with SCExAO
• Application of a damped Locally Optimized Combination of Images method to the spectral characterization of faint companions using an Integral Field Spectrograph
• High Contrast Imaging with an Arbitrary Aperture: Active Correction of Aperture Discontinuities
• DARKNESS: A Microwave Kinetic Inductance Detector Integral Field Spectrograph for High-Contrast Astronomy
• Wavefront error correction and Earth-like planet detection by Self-Coherent Camera in space
• The W. M. Keck Observatory infrared vortex coronagraph and a first image of HIP79124 B
• Estimation and correction of wavefront aberrations using the self-coherent camera: laboratory results
• Recursive Starlight and Bias Estimation for High-Contrast Imaging with an Extended Kalman Filter
• High-contrast imaging in polychromatic light with the self-coherent camera
• Focal Plane Wavefront Sensing using Residual Adaptive Optics Speckles
• Kalman filtering techniques for focal plane electric field estimation
• Speckle Control with a remapped-pupil PIAA-coronagraph
• Speckle suppression and companion detection using coherent differential imaging
• Fast & Furious focal-plane wavefront sensing
• Active correction of aperture discontinuities - optimized stroke minimization II: optimization for future missions
• The SPICA coronagraphic instrument (SCI) for the study of exoplanets
• Coronagraphic phase diversity: performance study and laboratory demonstration
• Focal plane wavefront sensor achromatization : The multireference self-coherent camera
• On High-Contrast Characterization of Nearby, Short-Period Exoplanets with Giant Segmented-Mirror Telescopes
• Focal-plane wavefront sensing with the vector Apodizing Phase Plate
• Comparing focal plane wavefront control techniques:\\Numerical simulations and laboratory experiments
• High-contrast imager for Complex Aperture Telescopes (HiCAT): 3. first lab results with wavefront control
• Dark Hole Maintenance and A Posteriori Intensity Estimation in the Presence of Speckle Drift in a High-Contrast Space Coronagraph
• Imaging exoplanets with coronagraphic instruments
• Active correction of aperture discontinuities - optimized stroke minimization I: a new adaptive interaction matrix algorithm
• Increasing the raw contrast of VLT/SPHERE with the dark hole technique. I. Simulations and validation on the internal source
• Analytical tolerancing of segmented telescope co-phasing for exo-Earth high-contrast imaging
• Closed-loop focal plane wavefront control with the SCExAO instrument
• Fast Coherent Differential Imaging on Ground-Based Telescopes using the Self-Coherent Camera
• Increasing the raw contrast of VLT/SPHERE with the dark-hole technique. II. On-sky wavefront correction and coherent differential imaging
• Electric Field Conjugation with the Project 1640 coronagraph
• Microelectromechanical deformable mirror development for high-contrast imaging, part 2: the impact of quantization errors on coronagraph image contrast
• Phase Quantization Study of Spatial Light Modulator for Extreme High contrast Imaging
• Imaging faint brown dwarf companions close to bright stars with a small, well-corrected telescope aperture
• Precise Wavefront Correction with an Unbalanced Nulling Interferometer for Exo-Planet Imaging Coronagraphs
• Atmospheric characterization of cold exoplanets using a 1.5-m coronagraphic space telescope
• Apodization in high-contrast long-slit spectroscopy. II. Concept validation and first on-sky results with VLT/SPHERE
• Active minimization of non-common path aberrations in long-exposure imaging of exoplanetary systems
• Active compensation of aperture discontinuities for WFIRST-AFTA: analytical and numerical comparison of propagation methods and preliminary results with a WFIRST-AFTA-like pupil
• Active correction of aperture discontinuities (ACAD) for space telescope pupils: a parametic analysis
• High-Resolution Altitude Profiles of the Atmospheric Turbulence with PML at the Sutherland Observatory
• Minimization of non common path aberrations at the Palomar telescope using a self-coherent camera
• High-contrast imaging at small separation: impact of the optical configuration of two deformable mirrors on dark holes
• Fainter and closer: finding planets by symmetry breaking
• Broadband Focal Plane Wavefront Control of Amplitude and Phase Aberrations
• Status and performance of the THD2 bench in multi-deformable mirror configuration
• An iterative wave-front sensing algorithm for high-contrast imaging systems
• First on-sky demonstration of spatial Linear Dark Field Control with the vector-Apodizing Phase Plate at Subaru/SCExAO
• Speckle noise reduction techniques for high-dynamic range imaging
• High-Contrast Coronagraphy
• Focal plane wave-front sensing algorithm for high-contrast imaging
• Coronagraph Experiment on Dark-hole Control by Speckle Area Nulling Method
• Laboratory Demonstration of Spatial Linear Dark Field Control For Imaging Extrasolar Planets in Reflected Light
• A Chromaticity Analysis and PSF Subtraction Techniques for SCExAO/CHARIS data
• Fast focal plane wavefront sensing on ground-based telescopes
• High contrast at small separation -- II. Impact on the dark hole of a realistic optical set-up with two deformable mirrors
• Low-order wavefront control using a Zernike sensor through Lyot coronagraphs for exoplanet imaging: II. Concurrent operation with stroke minimization
• A Statistical Framework for the Utilization of Simultaneous Pupil Plane and Focal Plane Telemetry for Exoplanet Imaging, Part I: Accounting for Aberrations in Multiple Planes
• Focal Plane Wavefront Sensing with the FAST TGV Coronagraph
• Laboratory demonstration of a cryogenic deformable mirror for wavefront correction of space-borne infrared telescopes
• Fundamental limits to high-contrast wavefront control
• Direct Detection of Planets Orbiting Large Angular Diameter Stars: Sensitivity of an Internally-Occulting Space-Based Coronagraph
• Opening a new window to other worlds with spectropolarimetry
• Experimental parametric study of the self-coherent camera
• High-Contrast Integral Field Spectrograph (HCIFS): multi-spectral wavefront control and reduced-dimensional system identification
• Capabilities of ACAD-OSM, an active method for the correction of aperture discontinuities
• Wavefront retrieval through random pupil plane phase probes: Gerchberg-Saxton approach
• Coronagraphic demonstration experiment using aluminum mirrors for space infrared astronomical observations
• RHAPSODIE: Reconstruction of High-contrAst Polarized SOurces and Deconvolution for cIrcumstellar Environments
• High Speed Focal Plane Wavefront Sensing with an Optical Chopper
• Random Vibration Testing of Microelectromechanical Deformable Mirrors for Space-based High-Contrast Imaging
• Efficient wavefront sensing for space-based adaptive optics
• Identification and adaptive control of a high-contrast focal plane wavefront correction system
• Pair-based Analytical model for Segmented Telescopes Imaging from Space (PASTIS) for sensitivity analysis
• A Statistical Framework for Utilization of Simultaneous Pupil Plane and Focal Plane Telemetry for Exoplanet Imaging, Part II: The Science Camera Image as a Function of the Wavefront Sensor Field
• Low-order wavefront control using a Zernike sensor through Lyot coronagraphs for exoplanet imaging
• Improving VLT/SPHERE without additional hardware: Comparing quasi-static correction strategies
• The coherent differential imaging on speckle area nulling (CDI-SAN) method for high-contrast imaging under speckle variation
• Diffraction-dominated observational astronomy