ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., IV-2/W4, 477-484, 2017
https://doi.org/10.5194/isprs-annals-IV-2-W4-477-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
 
14 Sep 2017
ESTIMATION OF PHASE DELAY DUE TO PRECIPITABLE WATER FOR DINSARBASED LAND DEFORMATION MONITORING
J. Susaki1, N. Maeda1, and S. Akatsuka2 1Department of Civil and Earth Resources Engineering, Graduate School of Engineering, Kyoto University; Kyotodaigakukatsura, Nishikyo-ku, Kyoto 615-8540, Japan
2School of Systems Engineering, Kochi University of Technology; 185, Miyanokuchi, Tosayamada, Kami, Kochi 782-8502, Japan
Keywords: Precipitable water, Differential interferometric SAR, Atmospheric phase delay Abstract. In this paper, we present a method for using the estimated precipitable water (PW) to mitigate atmospheric phase delay in order to improve the accuracy of land-deformation assessment with differential interferometric synthetic aperture radar (DInSAR). The phase difference obtained from multi-temporal synthetic aperture radar images contains errors of several types, and the atmospheric phase delay can be an obstacle to estimating surface subsidence. In this study, we calculate PW from external meteorological data. Firstly, we interpolate the data with regard to their spatial and temporal resolutions. Then, assuming a range direction between a target pixel and the sensor, we derive the cumulative amount of differential PW at the height of the slant range vector at pixels along that direction. The atmospheric phase delay of each interferogram is acquired by taking a residual after a preliminary determination of the linear deformation velocity and digital elevation model (DEM) error, and by applying high-pass temporal and low-pass spatial filters. Next, we estimate a regression model that connects the cumulative amount of PW and the atmospheric phase delay. Finally, we subtract the contribution of the atmospheric phase delay from the phase difference of the interferogram, and determine the linear deformation velocity and DEM error. The experimental results show a consistent relationship between the cumulative amount of differential PW and the atmospheric phase delay. An improvement in land-deformation accuracy is observed at a point at which the deformation is relatively large. Although further investigation is necessary, we conclude at this stage that the proposed approach has the potential to improve the accuracy of the DInSAR technique.
Conference paper (PDF, 2434 KB)


Citation: Susaki, J., Maeda, N., and Akatsuka, S.: ESTIMATION OF PHASE DELAY DUE TO PRECIPITABLE WATER FOR DINSARBASED LAND DEFORMATION MONITORING, ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., IV-2/W4, 477-484, https://doi.org/10.5194/isprs-annals-IV-2-W4-477-2017, 2017.

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