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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B2. Istanbul 2004 
USE OF GEOSTATISTICS TO INTEGRATE INTERFEROMETRIC 
SAR DATA WITH LEVELING MEASUREMENTS OF LAND 
SUBSIDENCE 
Alfred Stein®**and Yueqin Zhou? 
* TTC, International Institute for Geo-Information Science and Earth Observation 
PO Box 6, 7500 AA Enschede 
The Netherlands 
PS ICWG II/IV Automated Geo-spatial Data Production and Updating 
Abstract D-InSAR data of ground surface deformation have uncertainty caused by several sources associated 
with image acquisitions and data processing. In this study, these data are modeled as the sum of a trend. a zero- 
mean stochastic process and white noise. The aim is to improve their accuracy by correcting the errors using 
measurements as the ground truth. A geostatistical approach integrates D-InSAR subsidence data with im situ 
leveling measurements. Discrepancies between the true subsidence values and original D-InSAR. measurements are 
analyzed at leveling points using variograms and predicted at unvisited points using kriging. The proposed method 
is applied to the data collected in the where land subsidence occurs due to groundwater extraction in the Tianjin 
area in China. Results demonstrate the capability of D-InSAR to detect subsidence at the cm-level, and of using 
a limited number of leveling points to improve the accuracy of D-InSAR deformation measurements provided the 
coherence of images used is high enough. In addition, localization of leveling points is optimized. 
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