Coherent Change Detection (CCD) using multi-temporal Synthetic Aperture Radar (SAR) is one of the most important applications of remote sensing technology. With the advent of high-resolution SAR images, CCD has received a lot of attention. In CCD, the interferometric coherence between two SAR images is evaluated and analyzed to detect surface changes. Unfortunately, the sample coherence estimator is biased, especially for low-coherence values. The consequence of this bias is the apparition of highly coherent pixels inside the changed area. Within this context, the detection performance will considerably degrade, particularly when using high resolution SAR data. In this paper, we propose a new CCD method based on cleaning of coherence inside changed areas, which is characterized by high Local Fringe Frequencies (LFF) values, followed by a space-averaged coherence method. According to the proposed method, the results obtained with Cosmo-SkyMed (CSK) SAR data show an enhancement of change detection performance of about 6% while preserving subtle changes.
2. Rignot, E. J., "Change detection techniques for ERS-1 SAR data," IEEE Trans. Geosci. Remote Sens., Vol. 31, No. 4, 896-906, 1993.
3. Corr, D. G., "Coherent change detection of vehicle movements," Proc. IGARSS, Vol. 5, 2451-2453, 1998.
4. Touzi, R., "Coherence estimation for SAR imagery," IEEE Trans. Geosci. Remote Sens., Vol. 37, No. 1, 135-149, 1999.
5. Preiss, M., "Detecting scene changes using synthetic aperture radar interferometry," IEEE Trans. Geosci. Remote Sens., Vol. 44, No. 8, 2041-2054, 2006.
6. Sabry, R., "A new coherency formalism for change detection and phenomenology in SAR imagery: A field approach ," IEEE Geosc. and Remote Sens. Letters, Vol. 6, No. 3, 458-462, 2009.
7. Oishi, N., "A coherence improvement technique for coherent change detection in SAR interferometry," Proc. of the 6th European Radar Conference, Rome, Italy, Sep. 30-Oct. 2, 2009.
8. Phillips, R. D., "Clean: A false alarm reduction method for SAR CCD," 2011 IEEE Int. Conf. on Acoustics, Speech and Signal Processing (ICASSP), 1365-1368, May 2011.
9. Bouaraba, A., A. Younsi, A. Belhadj Aissa, M. Acheroy, N. Milisavljevic, and D. Closson , "Robust techniques for coherent change detection using Cosmo-SkyMed SAR images," Progress In Electromagnetics Research M, Vol. 22, 219-232, 2012.
10. Martinez, C. L., "Coherence estimation in synthetic aperture radar data based on speckle noise modeling," Applied Optics, Vol. 46, No. 4, 544-558, 2007.
11. Bamler, R., "Synthetic aperture radar interferometry," Inverse Problems, Vol. 14, No. 2, 1-54, 1998.
12. Lee, J. S., "Intensity and phase statistics of multilook polarimetric and interferometric SAR imagery," IEEE Trans. Geosci. Remote Sens., Vol. 32, No. 5, 1017-1028, 1994.
13. Trouve, E., "Improving phase unwrapping techniques by the use of local frequency estimates," IEEE Trans. Geosci. Remote Sens., Vol. 36, No. 6, 1963-1972, 1998.
14. Vasile, G., "High-resolution SAR interferometry: Estimation of local frequencies in the context of alpine glaciers," IEEE Trans. Geosci. Remote Sens., Vol. 46, No. 4, 1079-1090, 2008.
15. Suo, Z., "A new strategy to estimate local fringe frequencies for InSAR phase noise reduction ," IEEE Trans. Geosci. Remote Sens. Lett., Vol. 7, No. 40, 771-775, 2010.
16. Spagnolini, U., "2-D phase unwrapping and instantaneous frequency estimation," IEEE Trans. Geosci. Remote Sens., Vol. 33, No. 5, 579-589, 1995.
17. Trouve, E., "Fringe detection in noisy complex interferograms," Applied Optics, Vol. 35, No. 20, 3799-3806, 1996.