The flat-field method based on rotated images for FY-3E/X-EUVI
An algorithm to calculate the flat-field coefficient based on the series of rotated images captured by the solar X-ray and Extreme Ultraviolet Imager (X-EUVI) onboard the Fengyun-3E satellite is proposed in this article. The method includes determination of the solar disk centers and radiuses, calcu...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2022-10-01
|
| Series: | Frontiers in Physics |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fphy.2022.1048835/full |
| _version_ | 1797986408834531328 |
|---|---|
| author | Guangxing Ding Kun Wu Lingping He Bo Chen Fei Liu |
| author_facet | Guangxing Ding Kun Wu Lingping He Bo Chen Fei Liu |
| author_sort | Guangxing Ding |
| collection | DOAJ |
| description | An algorithm to calculate the flat-field coefficient based on the series of rotated images captured by the solar X-ray and Extreme Ultraviolet Imager (X-EUVI) onboard the Fengyun-3E satellite is proposed in this article. The method includes determination of the solar disk centers and radiuses, calculation of the rotation angles, coordinate transformation to expand the solar disk into rectangles, and derivation of the flat matrix using the KLL algorithm. The accuracy of determination of the solar disk center and radius tested by the Hough gradient method and the least-squares method is at sub-pixel, and the precision of the calculated rotation angle based on the log-polar transform is less than 0.025°. Since the X-EUVI rotates relative to the Sun in real time, multiple rotating images can be obtained and used for flat-field calibration at any time, and the tested accuracy is estimated at 0.79–3.42%. This flat-field method will provide reference and support for solar image processing and research. |
| first_indexed | 2024-04-11T07:33:31Z |
| format | Article |
| id | doaj.art-d986f772c50c4f10ab909f02af6eab89 |
| institution | Directory Open Access Journal |
| issn | 2296-424X |
| language | English |
| last_indexed | 2024-04-11T07:33:31Z |
| publishDate | 2022-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Physics |
| spelling | doaj.art-d986f772c50c4f10ab909f02af6eab892022-12-22T04:36:49ZengFrontiers Media S.A.Frontiers in Physics2296-424X2022-10-011010.3389/fphy.2022.10488351048835The flat-field method based on rotated images for FY-3E/X-EUVIGuangxing Ding0Kun Wu1Lingping He2Bo Chen3Fei Liu4Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences (CAS), Changchun, ChinaChangchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences (CAS), Changchun, ChinaChangchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences (CAS), Changchun, ChinaChangchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences (CAS), Changchun, ChinaSchool of Optoelectronic Engineering, Xidian University, Xi'an, ChinaAn algorithm to calculate the flat-field coefficient based on the series of rotated images captured by the solar X-ray and Extreme Ultraviolet Imager (X-EUVI) onboard the Fengyun-3E satellite is proposed in this article. The method includes determination of the solar disk centers and radiuses, calculation of the rotation angles, coordinate transformation to expand the solar disk into rectangles, and derivation of the flat matrix using the KLL algorithm. The accuracy of determination of the solar disk center and radius tested by the Hough gradient method and the least-squares method is at sub-pixel, and the precision of the calculated rotation angle based on the log-polar transform is less than 0.025°. Since the X-EUVI rotates relative to the Sun in real time, multiple rotating images can be obtained and used for flat-field calibration at any time, and the tested accuracy is estimated at 0.79–3.42%. This flat-field method will provide reference and support for solar image processing and research.https://www.frontiersin.org/articles/10.3389/fphy.2022.1048835/fullflat fieldsolar imageHough gradientKLL algorithmcanny operator |
| spellingShingle | Guangxing Ding Kun Wu Lingping He Bo Chen Fei Liu The flat-field method based on rotated images for FY-3E/X-EUVI Frontiers in Physics flat field solar image Hough gradient KLL algorithm canny operator |
| title | The flat-field method based on rotated images for FY-3E/X-EUVI |
| title_full | The flat-field method based on rotated images for FY-3E/X-EUVI |
| title_fullStr | The flat-field method based on rotated images for FY-3E/X-EUVI |
| title_full_unstemmed | The flat-field method based on rotated images for FY-3E/X-EUVI |
| title_short | The flat-field method based on rotated images for FY-3E/X-EUVI |
| title_sort | flat field method based on rotated images for fy 3e x euvi |
| topic | flat field solar image Hough gradient KLL algorithm canny operator |
| url | https://www.frontiersin.org/articles/10.3389/fphy.2022.1048835/full |
| work_keys_str_mv | AT guangxingding theflatfieldmethodbasedonrotatedimagesforfy3exeuvi AT kunwu theflatfieldmethodbasedonrotatedimagesforfy3exeuvi AT lingpinghe theflatfieldmethodbasedonrotatedimagesforfy3exeuvi AT bochen theflatfieldmethodbasedonrotatedimagesforfy3exeuvi AT feiliu theflatfieldmethodbasedonrotatedimagesforfy3exeuvi AT guangxingding flatfieldmethodbasedonrotatedimagesforfy3exeuvi AT kunwu flatfieldmethodbasedonrotatedimagesforfy3exeuvi AT lingpinghe flatfieldmethodbasedonrotatedimagesforfy3exeuvi AT bochen flatfieldmethodbasedonrotatedimagesforfy3exeuvi AT feiliu flatfieldmethodbasedonrotatedimagesforfy3exeuvi |