Retrieval of Spherical Ocean Wave Parameters Using RADARSAT-2 SAR Sensor Observed at Chukk, Micronesia
KCI
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Title
- Retrieval of Spherical Ocean Wave Parameters Using RADARSAT-2 SAR Sensor Observed at Chukk, Micronesia
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Author(s)
- Sudhir Kum; 양찬수; 송정환; Kazuo Ouchi; P. Shanmugam
- KIOST Author(s)
- Yang, Chan Su(양찬수)
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Alternative Author(s)
- Sudhir Kum; 양찬수; 송정환
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Publication Year
- 2011-06
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Abstract
- The purpose of this study is to estimate the spherical wave parameters that appears in synthetic aperture radar (SAR) image acquired over the coast of Chukk, Micronesia. The retrieval of ocean wave parameters consists of two main stages: the first is to determine the dominant wavelengths by Fast Fourier Transform (FFT) over 16 sub-image areas and the second is to estimate wave slopes and heights using dispersion relationship under various water wave conditions. It is assumed that the spherical waves are linear and progressive. These type of waves have the range and azimuth components traveling in radial directions. The azimuth travelling waves are more affected by the velocity bunching mechanism and it is difficult to estimate the wave parameters for these affected areas in SAR imagery. In order to compensate these effects, the velocity bunching ratio (VBR) based on modulation transfer function (MTF) was compared with the intensity ratio for neighbor area in the radial direction in order to assign the spherical wave properties for azimuthally travelling waves. Dispersion relation provides the good estimates for the wave heights for all the selected sub-image areas in the range of 1m to 2m. VBR based on MTF was found to be 0.78 at wave height of 1.36m, while the intensity-based VBR was 0.69 which corresponds to the height of 1.75m. It can be said that the velocity bunching accounts for azimuthally travelling spherical waves and the difference results from the sea-bottom effects.
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ISSN
- 1225-6161
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URI
- https://sciwatch.kiost.ac.kr/handle/2020.kiost/3859
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Bibliographic Citation
- 대한원격탐사학회지, v.27, no.3, pp.213 - 223, 2011
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Publisher
- 대한원격탐사학회
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Keywords
- Spherical waves; Wave parameters; FFT; SAR_ocean imaging; Dispersion relation; Velocity bunching
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Type
- Article
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Language
- English
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