Phase-diversity wave-front sensor for imaging systems

Kendrick, Richard L.; Acton, D. Scott; Duncan, A. L.

doi:10.1364/ao.33.006533

Cited by 92 publications

(36 citation statements)

References 5 publications

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“…The first one, which is called the standard image I These two images are used to compute a phase criterion χ ref that does not depend on the target intensity distribution and is a relevant signature of the actual piston errors. Kendrick et al (1994) proposed four different metrics to define the χ criterion…”

Section: Phase Diversitymentioning

confidence: 99%

Co-phasing of a diluted aperture synthesis instrument for direct imaging: Experimental demonstration on a temporal hypertelescope

Bouyeron¹,

Delage²,

Grossard³

et al. 2012

A&A

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Context. The diluted aperture synthesis is one of the most promising ways of obtaining direct images with an angular resolution in the milliarcsecond range. By applying apodization techniques to a hypertelescope, it is possible to discriminate between objects with a high contrast in intensity with a reasonable number of telescopes (<10). Aims. To reach such performances, we attempt to develop a co-phasing system capable of stabilizing the optical path differences with an accuracy better than λ/100 RMS. Methods. We propose a method based on a joint use of a sub-aperture piston phase-diversity technique and a genetic algorithm to co-phase a laboratory prototype called a temporal hypertelescope (THT). First, we simulated the behavior of this instrument and inferred the related statistical properties of our co-phasing method. In a second step, we implemented this co-phasing system on our THT prototype. Results. We obtain an experimental stabilization of the optical path differences of about λ/300 RMS over 1000 s. Thanks to this result, we are able to acquire an image of a high-contrast binary system. We also validate that the instrument accurately estimates the object characteristics, i.e. 25 μrad for the angular separation and ΔH = 9.1 magnitude difference between the main star and its companion.

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Section: Phase Diversitymentioning

confidence: 99%

Co-phasing of a diluted aperture synthesis instrument for direct imaging: Experimental demonstration on a temporal hypertelescope

Bouyeron¹,

Delage²,

Grossard³

et al. 2012

A&A

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show abstract

“…Some algorithmic developments were leaded in parallel to optimize the noise reduction [15] or to reduce computation time for cophasing applications [16]. To be exhaustive, we should mention some tests with phase diversity in real time control of an adaptive optics system on extended scene for astronomy [17]. The RASCASSE project have been thought as a whole study gathering numerical simulations and experience of these two wave-front sensors: Shack-Hartmann, and phase diversity.…”

Section: I2 State-of-the Art Of the Wave-front Sensors For Space Appmentioning

confidence: 99%

Wave-front sensing for space active optics: Rascasse project

Liotard

Bernot

Carlavan

et al. 2017

International Conference on Space Optics — ICSO 2014

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“…PCA is used for extracting {p k }, which is described in section 3.2. For the architecture of the learning system, the generalized regression neural network (GRNN), of which the response function of neurons consists of a radial basis function, is used for the estimation of aberration parameters 12) . By means of GRNN, a is represented as a function of {p k }.…”

Section: Estimation Of Aberration Parameters From Observed Imagesmentioning

confidence: 99%

On-Orbit Self-Compensation of Satellite Optics Using Spatial Light Modulator

Miyamura

2010

AEROSPACE TECHNOLOGY JAPAN

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We propose an adaptive optics system for a lightweight remote sensing sensor. The phase diversity (PD) technique, in which known wavefronts (Phase Diversity) are applied to the optics and the inherent aberrations are estimated using the acquired images without a priori information, is a key to realizing the system. For the reduction of computing cost and the enhancement of the estimation accuracy of aberration, a spatial light modulator (SLM) is adopted not only for wavefront compensator but also for PD generator. The SLM produces arbitrary "aberration modes" that are each represented by a Zernike polynomial. Therefore, optimal phase diversities are applied to the optical system and particular modes are effectively obtained, which makes it possible to overcome the conventional PD generated by defocusing that describes only quadratic form and lacks information of a particular mode. In order to solve the complex inverse problem of phase diversity with low computing cost, a general regression neural network (GRNN) is used. Moreover, principal component analysis compresses the input data for GRNN by extracting information from collected images in Fourier space, and reduces computation cost considerably. The performance is validated by numerical simulation, and the result of experiment using SLM is described.

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Phase-diversity wave-front sensor for imaging systems

Cited by 92 publications

References 5 publications

Co-phasing of a diluted aperture synthesis instrument for direct imaging: Experimental demonstration on a temporal hypertelescope

Co-phasing of a diluted aperture synthesis instrument for direct imaging: Experimental demonstration on a temporal hypertelescope

Wave-front sensing for space active optics: Rascasse project

On-Orbit Self-Compensation of Satellite Optics Using Spatial Light Modulator

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