Comparison and Analysis of Geometric Correction Models of Spaceborne SAR
Following the development of synthetic aperture radar (SAR), SAR images have become increasingly common. Many researchers have conducted large studies on geolocation models, but little work has been conducted on the available models for the geometric correction of SAR images of different terrain. To...
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MDPI AG
2016-06-01
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| Series: | Sensors |
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| Online Access: | http://www.mdpi.com/1424-8220/16/7/973 |
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| author | Weihao Jiang Anxi Yu Zhen Dong Qingsong Wang |
| author_facet | Weihao Jiang Anxi Yu Zhen Dong Qingsong Wang |
| author_sort | Weihao Jiang |
| collection | DOAJ |
| description | Following the development of synthetic aperture radar (SAR), SAR images have become increasingly common. Many researchers have conducted large studies on geolocation models, but little work has been conducted on the available models for the geometric correction of SAR images of different terrain. To address the terrain issue, four different models were compared and are described in this paper: a rigorous range-doppler (RD) model, a rational polynomial coefficients (RPC) model, a revised polynomial (PM) model and an elevation derivation (EDM) model. The results of comparisons of the geolocation capabilities of the models show that a proper model for a SAR image of a specific terrain can be determined. A solution table was obtained to recommend a suitable model for users. Three TerraSAR-X images, two ALOS-PALSAR images and one Envisat-ASAR image were used for the experiment, including flat terrain and mountain terrain SAR images as well as two large area images. Geolocation accuracies of the models for different terrain SAR images were computed and analyzed. The comparisons of the models show that the RD model was accurate but was the least efficient; therefore, it is not the ideal model for real-time implementations. The RPC model is sufficiently accurate and efficient for the geometric correction of SAR images of flat terrain, whose precision is below 0.001 pixels. The EDM model is suitable for the geolocation of SAR images of mountainous terrain, and its precision can reach 0.007 pixels. Although the PM model does not produce results as precise as the other models, its efficiency is excellent and its potential should not be underestimated. With respect to the geometric correction of SAR images over large areas, the EDM model has higher accuracy under one pixel, whereas the RPC model consumes one third of the time of the EDM model. |
| first_indexed | 2024-04-14T03:33:38Z |
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| id | doaj.art-3d0dd06d861f47279bf4df065346806c |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-14T03:33:38Z |
| publishDate | 2016-06-01 |
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| spelling | doaj.art-3d0dd06d861f47279bf4df065346806c2022-12-22T02:14:52ZengMDPI AGSensors1424-82202016-06-0116797310.3390/s16070973s16070973Comparison and Analysis of Geometric Correction Models of Spaceborne SARWeihao Jiang0Anxi Yu1Zhen Dong2Qingsong Wang3College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, ChinaCollege of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, ChinaCollege of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, ChinaEquipment Academy of the Rocket Force, Beijing 100085, ChinaFollowing the development of synthetic aperture radar (SAR), SAR images have become increasingly common. Many researchers have conducted large studies on geolocation models, but little work has been conducted on the available models for the geometric correction of SAR images of different terrain. To address the terrain issue, four different models were compared and are described in this paper: a rigorous range-doppler (RD) model, a rational polynomial coefficients (RPC) model, a revised polynomial (PM) model and an elevation derivation (EDM) model. The results of comparisons of the geolocation capabilities of the models show that a proper model for a SAR image of a specific terrain can be determined. A solution table was obtained to recommend a suitable model for users. Three TerraSAR-X images, two ALOS-PALSAR images and one Envisat-ASAR image were used for the experiment, including flat terrain and mountain terrain SAR images as well as two large area images. Geolocation accuracies of the models for different terrain SAR images were computed and analyzed. The comparisons of the models show that the RD model was accurate but was the least efficient; therefore, it is not the ideal model for real-time implementations. The RPC model is sufficiently accurate and efficient for the geometric correction of SAR images of flat terrain, whose precision is below 0.001 pixels. The EDM model is suitable for the geolocation of SAR images of mountainous terrain, and its precision can reach 0.007 pixels. Although the PM model does not produce results as precise as the other models, its efficiency is excellent and its potential should not be underestimated. With respect to the geometric correction of SAR images over large areas, the EDM model has higher accuracy under one pixel, whereas the RPC model consumes one third of the time of the EDM model.http://www.mdpi.com/1424-8220/16/7/973spaceborne SARgeometric correctionRange-Dopplerrational polynomialpolynomialelevation |
| spellingShingle | Weihao Jiang Anxi Yu Zhen Dong Qingsong Wang Comparison and Analysis of Geometric Correction Models of Spaceborne SAR Sensors spaceborne SAR geometric correction Range-Doppler rational polynomial polynomial elevation |
| title | Comparison and Analysis of Geometric Correction Models of Spaceborne SAR |
| title_full | Comparison and Analysis of Geometric Correction Models of Spaceborne SAR |
| title_fullStr | Comparison and Analysis of Geometric Correction Models of Spaceborne SAR |
| title_full_unstemmed | Comparison and Analysis of Geometric Correction Models of Spaceborne SAR |
| title_short | Comparison and Analysis of Geometric Correction Models of Spaceborne SAR |
| title_sort | comparison and analysis of geometric correction models of spaceborne sar |
| topic | spaceborne SAR geometric correction Range-Doppler rational polynomial polynomial elevation |
| url | http://www.mdpi.com/1424-8220/16/7/973 |
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