DInSAR estimation of land motion using intermittent coherence with application to the South Derbyshire and Leicestershire coalfields

Abstract

Differential interferometric synthetic aperture radar (DInSAR) is a recognized remote sensing method for measuring the land motion occurring between two satellite radar acquisitions. Advanced DInSAR techniques such as persistent scatterers (PS) and small baseline methods are excellent over urban and rocky environments but generally poor over more rural and natural terrain where the signal can be intermittently good and bad. Here, we describe the ISBAS (Intermittent Small Baseline Subset) method, which appears to improve results over natural, woodland and agricultural terrain. This technique uses a multilooked, low-resolution approach, which is particularly suitable for deriving the linear components of subsidence for large-scale deformations. Application of the ISBAS method over a coal mining area in the UK indicates that it is able to significantly improve upon a standard small baseline approach.

The application of the Intermittent SBAS (ISBAS) InSAR method to the South Wales Coalfield, UK

“…Previous studies have shown similar types of motions within former coal mining areas in the UK, for instance in Stoke-on-Trent [11] [17] , Durham and Northumberland [1], and the South Derbyshire and Leicestershire Coalfields [30]), as well as overseas, for instance in south Limburg (The Netherlands) and across Germany and Belgium [9], with observed annual rates of ground uplift as high as a few centimetres per year. This paper will present the first ISBAS results for South Wales and compare them to standard SBAS results.…”

“…For the implementation of the ISBAS approach this value was used as a threshold to select coherent pixels within each interferogram, so that for each image pixel, only those interferograms showing coherence higher than 0.25 were kept for the subsequent processing steps, provided that the number of coherent layers for those pixels exceeded 50, which was used as threshold for the selection of intermittently coherent targets (see also [30]). This threshold allows a trade-off between uncertainty in the ISBAS solutions and spatial coverage of results to be adopted.…”

“…Computation of linear velocities was performed by following the methodology described by [30], and based on differential interferograms which were unwrapped by employing the SNAPHU algorithm [3]. Height errors, atmospheric components and time series were also computed using spatio-temporal filters based on the deterministic characterization of the various phase components.…”

“…This can often give an incomplete view of the spatial extent of deformation and, in many cases, may not detect the deformation at all. This paper presents results of a newly modified implementation of the SBAS processing methodology, known as Intermittent Small Baseline Subset (ISBAS), which was developed at the Nottingham Geospatial Institute of the University of Nottingham [30]. This technique differs from a standard SBAS approach as pixels within the input radar stack which are only coherent for subsets of the total time period to be processed are considered along with those deemed to be coherent throughout the time period processed.…”

On the Use of the ISBAS Acronym in InSAR Applications. Comment on Vajedian, S.; Motagh, M.; Nilfouroushan, F. StaMPS Improvement for Deformation Analysis in Mountainous Regions: Implications for the Damavand Volcano and Mosha Fault in Alborz. Remote Sens. 2015, 7, 8323–8347

“…We offer a wide selection of references below [2][3][4][5][6][7][8], each of which clearly identifies the ISBAS acronym as Intermittent SBAS. The first peer-reviewed journal [2] in this instance was in 2013 and so the use of the acronym certainly predates the Vajedian et al reference by at least two years.…”