Combining differential SAR interferometry and the probability integral method for three-dimensional deformation monitoring of mining areas

ABSTRACT

With the exploitation of coal resources, ground surface subsidence continues to occur in mining areas, destroying the ecological environment and significantly affecting the daily productivity and life of humans. The differential synthetic aperture radar interferometry (D-InSAR) technique is widely used to monitor ground surface deformation because of its unique advantages such as high accuracy and wide coverage. However, conventional D-InSAR technology provides only one-dimensional (1D) displacement monitoring along the radar line of sight (LOS). This article proposes a method based on an analysis of the mining subsidence law for true three-dimensional (3D) displacement monitoring by combining D-InSAR and a subsidence prediction model based on the probability integral method. In this approach, 1D displacement, obtained using D-InSAR, is then combined with the prediction model to obtain the 3D displacement of ground surface target points. Here, 3D displacement curves were obtained for the Fengfeng mining area (China) using RadarSat-2 images obtained on 9 January and 2 February 2011. True ground surface displacement was measured simultaneously by levelling when the 152under31 s working face was being exploited in Jiulong mine. Vertical displacement and inclined deformation calculated using the proposed method were compared with levelling survey data and the results showed average differences of 3.2 mm and 0.1 mm m⁻¹, respectively; the calculated maximum displacement in the east–west and south–north directions were 106 and 73 mm, respectively. The spatial distribution of the displacements was in accordance with the mining subsidence law. Thus, the new method can retrieve highly accurate 3D displacements caused by mining subsidence.

Acknowledgements

The authors are grateful to the anonymous reviewers for their valuable suggestions. The Gamma software was used in this study. The three-arc-second Shuttle Radar Topography Mission digital elevation model is available for free downloaded from http://www2.jpl.nasa.gov/srtm/cbanddataproducts.html.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 51574221]; Priority Academic Program Development of the Jiangsu Higher Education Institutions [grant number SZBF2011-6-B35]; Scientific Research Foundation of the Jiangsu Key Laboratory of Resources and Environmental Information Engineering [grant number JS201109]; and the Graduate Scientific Research Innovation Program of Jiangsu Province Ordinary University [grant number KYZZ16_0218].