| Author: | Yang, Xiaoting |
| Title: | Change detection by using CoVAmCoh method for InSAR imagery processing : a case study in New Territories, HK |
| Advisors: | Ding, Xiaoli (LSGI) |
| Degree: | M.Sc. |
| Year: | 2015 |
| Subject: | Synthetic aperture radar. Land use, Urban -- Remote sensing. Land use -- Remote sensing. Remote-sensing images. Hong Kong Polytechnic University -- Dissertations |
| Department: | Faculty of Construction and Environment |
| Pages: | x, 73 pages : color illustrations |
| Language: | English |
| Abstract: | Along with the rapid process of urbanization in the modern world, more and more researchers are committed to the study on urban development. Thanks to the advent of remote sensing technology, scientists have made good use of them to monitor the urban development and help people get a knowledge about their residential places in a more efficient and effective way. Among them, Synthetic Aperture Radar (SAR) is outstanding for its independence of weather condition and natural illumination. Thus, it has become an important research topic to apply SAR or SAR Interferometry(InSAR) techniques to environmental research, hazard monitoring and topographic mapping, etc. Since the new generation of spaceborne SAR satellites (like TerraSAR-X) was launched in 2007, the high resolution and short revisit period of these systems have benefited a series of researches especially for time series study. In terms of the change detection and land cover classification in urban areas, the additional information that SAR systems provide - phase variation is meaningful to the image interpretation. Therefore, it is necessary to find an appropriate method for image processing, in support of users' demand on the interpretation of SAR images. In view of this, this dissertation demonstrates a new method proposed by Karsten Schulz ([11]), called CoVAmCoh. Instead of traditional methods which analyze intensity and phase information separately, this method makes use of three aspects of information: Coefficient of Variation, Amplitude and Coherence, then visualizes them in a RGB composite image. The method aims to provide users with an efficient and effective way for change detection and land cover type interpretation in urban area. To validate its application, a case study of a sub-urban area in New Territories, HK is conducted in this dissertation. In terms of the experiment results, a visual comparison and a simple statistical analysis are presented subsequently. Furthermore, in Section 6.1, we summarized its achievements from three aspects - enhanced visual effect, land cover type interpretation and change detection of anthropogenic activities. Regarding its future work, a quantitative analysis of change detection and an interpretation of mixed colors need to be emphasized for the improvement of CoVAmCoh method. What's more, applying this method for a broad database and C-band SAR imagery, selecting appropriate thresholds for layer processing, as well as estimating an unbiased coherence have been proposed in several previous literatures ([39],[41]) for further research directions. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b28315923.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.89 MB | Adobe PDF | View/Open |
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