An innovative distributed scatterer based time-series InSAR method over underground mining region

摘要

Advanced Time series InSAR (ATS-InSAR) is generally refer to those TS-InSAR methods with an external Distributed Scatterer (DS) selection module, e.g. SqueeSAR and GEOS-ATSA. It is being known as a very efficient tool for monitoring the ground deformation over suburban or even non-urban regions with great success. However, within Appin Colliery, which is located in the southeastern corner of the Southern Coalfield, New South Wales (NSW), Australia. C-band ASAR based ATS-InSAR failed to produce reasonable outcome due to the underground mining effect. This paper presents a modified ATS-InSAR method for mapping the ground deformation over underground mining region. Firstly, traditional reliable DS pixels and Persistent Scatterer (PS) pixels are selected to form the initial triangular irregular network (TIN) reference network. Then the ground deformation and DEM error with respect to these Measurement Scatterer (MS) pixels are solved through a robust regression estimator. Due to the losses of coherence, the general underground mining pattern cannot be formed when using C-band image stacks. Therefore, in order to achieve the best detail, modified MS pixel selection method is conducted by including less reliable MS pixels based on a weighted least square method. Moreover, final result proved to be efficient to offer sufficient information to associated councils and department for risk management purpose.