Improved On-Orbit MTF Measurement Method Based on Point Source Arrays
The modulation transfer function (MTF) is a key characteristic used to assess the performance of optical remote sensing satellite sensors. MTF detection can directly measure a sensor’s two-dimensional (2D) point spread function (PSF); therefore, it has been applied to various high-resolution remote...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-08-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/15/16/4028 |
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| author | Litao Li Jiayang Cao Shaodong Wei Yonghua Jiang Xin Shen |
| author_facet | Litao Li Jiayang Cao Shaodong Wei Yonghua Jiang Xin Shen |
| author_sort | Litao Li |
| collection | DOAJ |
| description | The modulation transfer function (MTF) is a key characteristic used to assess the performance of optical remote sensing satellite sensors. MTF detection can directly measure a sensor’s two-dimensional (2D) point spread function (PSF); therefore, it has been applied to various high-resolution remote sensing satellites (e.g., Pleiades) using point sources. However, current point source methods mainly use 2D Gaussian functions to fit the discrete digital number (DN) of the point source on the image to extract the center of the point source and fit the PSF after encrypting multiple point sources; thus, noise robustness is poor and measurement accuracy varies widely. In this study, we developed a noise-resistant on-orbit MTF detection method based on the object space constraint among point source arrays. Utilizing object space constraint relationships among points in a point source array, a homography transformation model was established, enabling accurate extraction of sub-pixel coordinates for each point source response. Subsequently, aligning the luminosity distribution of all point sources concerning a reference point source, the encrypted PSF was obtained and then fitted to obtain the MTF. To validate the method, Gaofen-2 (GF-2) satellite images were used to conduct an in-orbit imaging experiment on the point source array of the Chinese Zhongwei remote sensing satellite calibration site. Compared with the Gaussian model methods, the proposed method yielded more accurate peak positions for each point source. Standard deviations of peak position constant ratios in along- and cross-track directions improved by 2.8 and 4.8 times, respectively. The root-mean-square error (RMSE) of the collinearity test results increased by 92%, and the noise resistance of the MTF curve improved by two times. Dynamic MTF values at the Nyquist frequency for the GF-2 panchromatic band in along- and cross-track directions were 0.0476 and 0.0705, respectively, and MTF values in different directions were well distinguished. |
| first_indexed | 2024-03-10T23:37:01Z |
| format | Article |
| id | doaj.art-d2faab55b5e243de8d70161bd4184811 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-10T23:37:01Z |
| publishDate | 2023-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-d2faab55b5e243de8d70161bd41848112023-11-19T02:53:32ZengMDPI AGRemote Sensing2072-42922023-08-011516402810.3390/rs15164028Improved On-Orbit MTF Measurement Method Based on Point Source ArraysLitao Li0Jiayang Cao1Shaodong Wei2Yonghua Jiang3Xin Shen4College of Urban and Environmental Sciences, Hubei Normal University, Huangshi 435002, ChinaCollege of Urban and Environmental Sciences, Hubei Normal University, Huangshi 435002, ChinaState Key Laboratory of Information Engineering in Surveying, Mapping, and Remote Sensing, Wuhan University, Wuhan 430079, ChinaSchool of Remote Sensing and Information Engineering, Wuhan University, Wuhan 430079, ChinaState Key Laboratory of Information Engineering in Surveying, Mapping, and Remote Sensing, Wuhan University, Wuhan 430079, ChinaThe modulation transfer function (MTF) is a key characteristic used to assess the performance of optical remote sensing satellite sensors. MTF detection can directly measure a sensor’s two-dimensional (2D) point spread function (PSF); therefore, it has been applied to various high-resolution remote sensing satellites (e.g., Pleiades) using point sources. However, current point source methods mainly use 2D Gaussian functions to fit the discrete digital number (DN) of the point source on the image to extract the center of the point source and fit the PSF after encrypting multiple point sources; thus, noise robustness is poor and measurement accuracy varies widely. In this study, we developed a noise-resistant on-orbit MTF detection method based on the object space constraint among point source arrays. Utilizing object space constraint relationships among points in a point source array, a homography transformation model was established, enabling accurate extraction of sub-pixel coordinates for each point source response. Subsequently, aligning the luminosity distribution of all point sources concerning a reference point source, the encrypted PSF was obtained and then fitted to obtain the MTF. To validate the method, Gaofen-2 (GF-2) satellite images were used to conduct an in-orbit imaging experiment on the point source array of the Chinese Zhongwei remote sensing satellite calibration site. Compared with the Gaussian model methods, the proposed method yielded more accurate peak positions for each point source. Standard deviations of peak position constant ratios in along- and cross-track directions improved by 2.8 and 4.8 times, respectively. The root-mean-square error (RMSE) of the collinearity test results increased by 92%, and the noise resistance of the MTF curve improved by two times. Dynamic MTF values at the Nyquist frequency for the GF-2 panchromatic band in along- and cross-track directions were 0.0476 and 0.0705, respectively, and MTF values in different directions were well distinguished.https://www.mdpi.com/2072-4292/15/16/4028point spread function (PSF)modulation transfer function (MTF)point source arrayZhongwei remote sensing calibration site |
| spellingShingle | Litao Li Jiayang Cao Shaodong Wei Yonghua Jiang Xin Shen Improved On-Orbit MTF Measurement Method Based on Point Source Arrays Remote Sensing point spread function (PSF) modulation transfer function (MTF) point source array Zhongwei remote sensing calibration site |
| title | Improved On-Orbit MTF Measurement Method Based on Point Source Arrays |
| title_full | Improved On-Orbit MTF Measurement Method Based on Point Source Arrays |
| title_fullStr | Improved On-Orbit MTF Measurement Method Based on Point Source Arrays |
| title_full_unstemmed | Improved On-Orbit MTF Measurement Method Based on Point Source Arrays |
| title_short | Improved On-Orbit MTF Measurement Method Based on Point Source Arrays |
| title_sort | improved on orbit mtf measurement method based on point source arrays |
| topic | point spread function (PSF) modulation transfer function (MTF) point source array Zhongwei remote sensing calibration site |
| url | https://www.mdpi.com/2072-4292/15/16/4028 |
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