Characterization of adaptive optics point spread function for anisoplanatic imaging. Application to stellar field deconvolution

Abstract

Abstract. The point spread function (PSF) of an adaptive optics system evolves in the Field Of View (FOV). This variation strongly limits the conventional deconvolution methods for the processing of wide FOV images. A theoretical expression of this PSF variation is derived. This expression is both validated on simulations and experimental data. It is then applied to the a posteriori processing of stellar fields. Using the available prior information about the object (point-like sources), this technique allows the restoration of the star parameters (positions and intensities) with a precision much better than the conventional methods, in a FOV much larger than the isoplanatic field.

Anisoplanatism effect on the E-ELT SCAO point spread function. A preserved coherent core across the field

“…Racine & Ellerbroek 1995;Ellerbroek 1997;Whiteley et al 1998). Only a few studies focused on the anisoplanatism effect on the PSF profile, or the profile of its Fourier transform, the optical transfer function (Chassat 1992;Troxel et al 1994;Fusco et al 2000).…”

Simulation model based approach for long exposure atmospheric point spread function reconstruction for laser guide star multiconjugate adaptive optics

“…(1) In order to yield the science TTR PSFR error curve displayed in solid in the upper left panel, an ad hoc Laplacian squared (also known as biharmonic) regularization matrix with ∼25% weight relative to the largest eigenvalue of Γ T Γ had to be included in the computation of Γ T Γ † in Eq. (11). The necessity to include this regularization term is not fully understood, but is believed to be related to the presence of wafflelike modes originating from the ShackHartman Fried geometry.…”

“…There is no anisoplanatism for such an observation since the NGS is the science target. Fusco et al in 2000 [11], and later Britton et al in 2005 [12], extended Véran's technique to capture a key missing component: angular anisoplanatism, providing the astronomical AO community a complete PSFR tool for classical NGS single-conjugate AO (SCAO) observations. SR errors of 4% in K-band are reported on the Palomar AO system (order 16 × 16) at the 5 m Hale Telescope for observations of a bright star separated by 21 arcsec from its companient star (28% measured companient SR versus 27% predicted SR), and 100 microarcsec differential astrometry for a 2 min exposure using 50 reference stars.…”

Spatial, Temporal, and Interchannel Image Data Fusion for Long‐Distance Terrestrial Observation Systems

“…Classical adaptive optics, which uses a single deformable mirror, provides correction for a limited field of view (FOV). Larger FOV corrections can be achieved by several deformable mirrors optically conjugated at various heights [30][31][32][33]. In modeling images with distortion caused by atmospheric turbulence, light from each point in the acquired scene is assumed to possess a slightly different tilt and low-order aberration, and it can be modeled by convolving a raw image with a space-variant pseudorandom point spread function [34].…”