A comparative study of coherence patterns by C-band and L-band interferometric SAR in tropical rain forest areas.
Abstract
The authors compared the applicability of coherence patterns between C-band SAR from ERS-1 and 2 and Lband SAR from JERS-1 for the purpose of monitoring the changes of tropical rain forest due to- deforestation. The test site was a southern part of Sumatra Island with 50 by 50 kilometers coverage. We used two tandem data pairs by ERS-1 and 2, two repeat-pass data pairs by ERS-2, and four repeat-pass pairs by JERS-1, which observation periods nearly correspond each other between ERS and JERS data pairs. We generated coherence images from all data pairs by interferometric processing, in which a complex correlation coefficient was computed in a small window area with three range pixels and nine azimuth lines by using two single-look complex SAR images co-registered precisely each other. The coherence patterns were compared between ERS tandem and JERS repeat-pass data pairs and between ERS repeat-pass and JERS repeat-pass data pairs. The first item for comparison was the degree of coincidence of coherence patterns with deforested/non-deforested areas. The second item was the similarity of two- dimensional power spectra of coherence patterns between ERS and JERS data pairs. Multi-temporal optical sensor images acquired by MOS-1/MESSR and SPOT/HRV were used as the references for identifying deforested areas. The result indicated that the quality of coherence patterns obtained from ERS repeat-pass pair was very poor and almost useless to detect deforested areas. On the other hand, the coherence patterns obtained from JERS repeat-pass pairs were proved to be almost compatible to those obtained from ERS tandem pairs, both of which were quite effective for detecting deforested areas. This result suggests the usefulness of repeat-pass interferometry by coming ALOS/PALSAR for the purpose of monitoring tropical rain forest changes.
- Publication:
-
34th COSPAR Scientific Assembly
- Pub Date:
- 2002
- Bibcode:
- 2002cosp...34E.851T