TY - GEN
T1 - RABASAR
T2 - 38th Annual IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2018
AU - Zhao, Weiying
AU - Deledalle, Charles Alban
AU - Denis, Loïc
AU - Maître, Henri
AU - Nicolas, Jean Marie
AU - Tupin, Florence
N1 - Publisher Copyright:
© 2018 IEEE.
PY - 2018/10/31
Y1 - 2018/10/31
N2 - In this paper, a generic method is proposed to reduce speckle in multi-temporal stacks of SAR images. The method is based on the computation of a “super-image”, with a large number of looks, by temporal averaging. Then, ratio images are formed by dividing each image of the multi-temporal stack by the “super-image”. In the absence of changes of the radiometry, the temporal fluctuations of the intensity at a given spatial location are due to the speckle phenomenon. In areas affected by temporal changes, fluctuations cannot be ascribed to speckle only but also to radiometric changes. The overall effect of the division by the “super-image” is the spatial stationarity improvement: ratio images are much more homogeneous than the original images. Therefore, filtering these ratio images with a speckle-reduction method is more effective, in terms of speckle suppression, than filtering the original multitemporal stack. After denoising of the ratio image, the despeckled multi-temporal stack is obtained by multiplication with the “super-image”. Results are presented and analyzed both on synthetic and real SAR data and show the interest of the proposed approach.
AB - In this paper, a generic method is proposed to reduce speckle in multi-temporal stacks of SAR images. The method is based on the computation of a “super-image”, with a large number of looks, by temporal averaging. Then, ratio images are formed by dividing each image of the multi-temporal stack by the “super-image”. In the absence of changes of the radiometry, the temporal fluctuations of the intensity at a given spatial location are due to the speckle phenomenon. In areas affected by temporal changes, fluctuations cannot be ascribed to speckle only but also to radiometric changes. The overall effect of the division by the “super-image” is the spatial stationarity improvement: ratio images are much more homogeneous than the original images. Therefore, filtering these ratio images with a speckle-reduction method is more effective, in terms of speckle suppression, than filtering the original multitemporal stack. After denoising of the ratio image, the despeckled multi-temporal stack is obtained by multiplication with the “super-image”. Results are presented and analyzed both on synthetic and real SAR data and show the interest of the proposed approach.
KW - Despeckling
KW - Multi-temporal SAR series
KW - Ratio image
KW - SAR
KW - Super-image
U2 - 10.1109/IGARSS.2018.8519161
DO - 10.1109/IGARSS.2018.8519161
M3 - Conference contribution
AN - SCOPUS:85064272195
T3 - International Geoscience and Remote Sensing Symposium (IGARSS)
SP - 4197
EP - 4200
BT - 2018 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2018 - Proceedings
PB - Institute of Electrical and Electronics Engineers Inc.
Y2 - 22 July 2018 through 27 July 2018
ER -