Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Light spot centroid calculation method for weak signal of Hartmann wavefront detector

A calculation method and detector technology, applied in the field of adaptive optics, can solve problems such as large error in centroid calculation

Active Publication Date: 2018-06-19
CHANGCHUN INST OF OPTICS FINE MECHANICS & PHYSICS CHINESE ACAD OF SCI
View PDF5 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0022] Aiming at the problem that the signal-to-noise ratio in the Hartmann wavefront detector is lower than 16, the calculation error of the centroid of the signal spot in the sub-area is large, and a centroid calculation method combined with weight filtering is proposed, that is, the centroid calculation method is used in the sub-area to approximate The Gaussian-like intensity distribution function on the smaller area of ​​the spot scale is used to perform correlation calculations, generate sub-area weight filter windows, and then use the weight filter window to perform weighted calculations on the intensity distribution on the sub-area to generate spot intensity distributions with greatly reduced noise. The purpose is to Reduce the influence of photon noise around the spot and improve the calculation accuracy of the center of mass of the spot, thereby improving the detection limit star magnitude of the Hartmann wavefront detector

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Light spot centroid calculation method for weak signal of Hartmann wavefront detector
  • Light spot centroid calculation method for weak signal of Hartmann wavefront detector
  • Light spot centroid calculation method for weak signal of Hartmann wavefront detector

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0042] The specific simulation process is as follows:

[0043] 1. The structural parameters of the Hartmann wavefront detector are: the aperture is 5.8mm, the number of microlenses is 20×20, arranged in a square, the diameter d of the microlenses is 288μm, the focal length is f=20.1mm, and the light wavelength λ=550nm; the back camera The readout noise of the CCD is negligible, the number of pixels of the CCD is 120×120, the number of pixels of the sub-area is 6×6, and the pixel size of the CCD is 24μm×24μm; the diameter of the Airy spot after the sub-wavefront passes through the microlens is 1.2λf / d=1.9 pixels, so that the light spot can cover about 3×3 pixels under the influence of the distorted wavefront.

[0044] 2. The detected target magnitude is 5.5, which exceeds the detection limit magnitude of the former Hartmann wavefront detector of the present invention, and the number of photoelectrons corresponding to the sub-region light spots is 100.

[0045] 3. Obtain the p...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention belongs to the technical field of adaptive optical imaging, and proposes a filtering method for solving a problem of big wavefront detection errors caused by the low signal to noise ratio of the weak signal. The basic idea of the invention is that the intensity distribution of each light spot of a Hartmann wavefront detector should be similar to the Gaussian-like intensity distribution function shown by drawing 1; the weight of a central intensity signal of a light spot will be highlighted and the weight of the edge photon noise of a subregion will be reduced if the Gaussian-likeintensity distribution function in a 3*3 pixel region is used for the correlation calculation with an intensity distribution function of a 6*6 pixel subregion, and a regional weight filtering windowW is formed; the range of W is also located in the 6*6 pixel subregion; an effective subregion weight filtering window W is also used for the weight calculation with the intensity distribution I of the subregion, thereby obtaining the intensity distribution of the light spot of a subregion with the noise being suppressed; and the centroid of the light spot of the subregion is calculated through acommon centroid algorithm. The method can enable the wavefront detection error (the magnitude of 5.5) to be reduced by 20%.

Description

technical field [0001] The invention belongs to the technical field of adaptive optics, and relates to a wavefront detection method based on a Hartmann wavefront detector. The calculation method involving the center of mass of the light spot when the signal-to-noise ratio of the Hartmann wavefront detector is low improves the detection limit star magnitude of the Hartmann wavefront detector. Background technique [0002] When a telescope is used to observe celestial objects, due to the random interference of atmospheric turbulence, the imaging light wavefront is dynamically distorted, resulting in a decrease in the imaging resolution of the telescope. Adaptive optics detects and corrects distorted wavefronts caused by atmospheric turbulence in real time to restore the telescope's ideal high-resolution imaging. The Hartmann wavefront detector is a widely used wavefront detector in current adaptive systems. The detector as figure 1 As shown, it consists of a front microlens...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): G01J9/00
CPCG01J9/00
Inventor 宣丽李大禹徐焕宇李明星张佩光张杏云姚丽双杨程亮曹召良穆全全彭增辉刘永刚王启东王玉坤王少鑫
Owner CHANGCHUN INST OF OPTICS FINE MECHANICS & PHYSICS CHINESE ACAD OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com