Evaluation of the Emissions State of a Satellite Laser Altimeter Based on Laser Footprint Imaging
The GaoFen-7(GF-7) satellite is equipped with China’s first laser altimeter for Earth observation; it has the capability of full waveform recording, which can obtain global high-precision three-dimensional coordinates over a wide range. The laser is inevitably affected by platform tremors, random er...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-02-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/14/4/1025 |
| _version_ | 1797476735658229760 |
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| author | Jiaqi Yao Haoran Zhai Shuqi Wu Zhen Wen Xinming Tang |
| author_facet | Jiaqi Yao Haoran Zhai Shuqi Wu Zhen Wen Xinming Tang |
| author_sort | Jiaqi Yao |
| collection | DOAJ |
| description | The GaoFen-7(GF-7) satellite is equipped with China’s first laser altimeter for Earth observation; it has the capability of full waveform recording, which can obtain global high-precision three-dimensional coordinates over a wide range. The laser is inevitably affected by platform tremors, random errors in the laser pointing angle, laser state, and other factors, which further affect the measurement accuracy of the laser footprint. Therefore, evaluation of the satellite laser launch state is an important process. This study contributes to laser emission state evaluations based on the laser footprint image in terms of two main two aspects: (1) Monitoring changes in the laser pointing angle—laser pointing is closely related to positioning accuracy, which mainly results from monitoring the change in the laser spot centroid. We propose a threshold constraint algorithm that extracts the centroid of an ellipse-fitting spot. (2) Analysis of the energy distribution state—directly obtaining the parameters used in the traditional evaluation method is a challenge for the satellite. Therefore, an index suitable for evaluating the laser emissions state of the GF-7 satellite was constructed according to the data characteristics. Based on these methods, long time-series data were evaluated and analyzed. The experimental results show that the proposed method can effectively evaluate the emissions state of the laser altimeter, during which the laser pointing angle changes monthly by 0.434″. During each continuous operation of the laser, the energy state decreased gradually, with a small variation range; however, both were generally in a stable state. |
| first_indexed | 2024-03-09T21:07:55Z |
| format | Article |
| id | doaj.art-22973cb6711f40bb9a1185430d27e848 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-09T21:07:55Z |
| publishDate | 2022-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-22973cb6711f40bb9a1185430d27e8482023-11-23T21:55:47ZengMDPI AGRemote Sensing2072-42922022-02-01144102510.3390/rs14041025Evaluation of the Emissions State of a Satellite Laser Altimeter Based on Laser Footprint ImagingJiaqi Yao0Haoran Zhai1Shuqi Wu2Zhen Wen3Xinming Tang4College of Geomatics, Shandong University of Science and Technology, Qingdao 266590, ChinaLand Satellite Remote Sensing Application Center, Ministry of Natural Resources, Beijing 100048, ChinaLand Satellite Remote Sensing Application Center, Ministry of Natural Resources, Beijing 100048, ChinaCollege of Geomatics, Shandong University of Science and Technology, Qingdao 266590, ChinaCollege of Geomatics, Shandong University of Science and Technology, Qingdao 266590, ChinaThe GaoFen-7(GF-7) satellite is equipped with China’s first laser altimeter for Earth observation; it has the capability of full waveform recording, which can obtain global high-precision three-dimensional coordinates over a wide range. The laser is inevitably affected by platform tremors, random errors in the laser pointing angle, laser state, and other factors, which further affect the measurement accuracy of the laser footprint. Therefore, evaluation of the satellite laser launch state is an important process. This study contributes to laser emission state evaluations based on the laser footprint image in terms of two main two aspects: (1) Monitoring changes in the laser pointing angle—laser pointing is closely related to positioning accuracy, which mainly results from monitoring the change in the laser spot centroid. We propose a threshold constraint algorithm that extracts the centroid of an ellipse-fitting spot. (2) Analysis of the energy distribution state—directly obtaining the parameters used in the traditional evaluation method is a challenge for the satellite. Therefore, an index suitable for evaluating the laser emissions state of the GF-7 satellite was constructed according to the data characteristics. Based on these methods, long time-series data were evaluated and analyzed. The experimental results show that the proposed method can effectively evaluate the emissions state of the laser altimeter, during which the laser pointing angle changes monthly by 0.434″. During each continuous operation of the laser, the energy state decreased gradually, with a small variation range; however, both were generally in a stable state.https://www.mdpi.com/2072-4292/14/4/1025GF-7satellite laser altimetrylaser footprint imagecentroid extractionstability analysis of pointing angle |
| spellingShingle | Jiaqi Yao Haoran Zhai Shuqi Wu Zhen Wen Xinming Tang Evaluation of the Emissions State of a Satellite Laser Altimeter Based on Laser Footprint Imaging Remote Sensing GF-7 satellite laser altimetry laser footprint image centroid extraction stability analysis of pointing angle |
| title | Evaluation of the Emissions State of a Satellite Laser Altimeter Based on Laser Footprint Imaging |
| title_full | Evaluation of the Emissions State of a Satellite Laser Altimeter Based on Laser Footprint Imaging |
| title_fullStr | Evaluation of the Emissions State of a Satellite Laser Altimeter Based on Laser Footprint Imaging |
| title_full_unstemmed | Evaluation of the Emissions State of a Satellite Laser Altimeter Based on Laser Footprint Imaging |
| title_short | Evaluation of the Emissions State of a Satellite Laser Altimeter Based on Laser Footprint Imaging |
| title_sort | evaluation of the emissions state of a satellite laser altimeter based on laser footprint imaging |
| topic | GF-7 satellite laser altimetry laser footprint image centroid extraction stability analysis of pointing angle |
| url | https://www.mdpi.com/2072-4292/14/4/1025 |
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