Mexico City land subsidence in 2014–2015 with Sentinel-1 IW TOPS: Results using the Intermittent SBAS (ISBAS) technique

Abstract

Differential Interferometric Synthetic Aperture Radar (DInSAR) can be considered as an efficient and cost effective technique for monitoring land subsidence due to its large spatial coverage and high accuracy provided. The recent commissioning of the first Sentinel-1 satellite offers improved support to operational surveys using DInSAR due to regular observations from a wide-area product. In this paper we show the results of an intermittent small-baseline subset (ISBAS) time-series analysis of 18 Interferometric Wide swath (IW) products of a 39,000 km 2 area of Mexico acquired between 3 October 2014 and 7 May 2015 using the Terrain Observation with Progressive Scans in azimuth (TOPS) imaging mode. The ISBAS processing was based upon the analysis of 143 small-baseline differential interferograms. After the debursting, merging and deramping steps necessary to process Sentinel-1 IW products, the method followed a standard approach to the DInSAR analysis. The Sentinel-1 ISBAS results confirm the magnitude and extent of the deformation that was observed in Mexico City, Chalco, Ciudad Nezahualcóyotl and Iztapalapa by other C-band and L-band DInSAR studies during the 1990s and 2000s. Subsidence velocities from the Sentinel-1 analysis are, in places, in excess of -24 cm/year along the satellite line-ofsight, equivalent to over ~-40 cm/year vertical rates. This paper demonstrates the potential of Sentinel-1 IW TOPS imagery to support wide-area DInSAR surveys over what is a very large and diverse area in terms of land cover and topography.

Monitoring land motion due to natural gas extraction: Validation of the Intermittent SBAS (ISBAS) DInSAR algorithm over gas fields of North Holland, the Netherlands

“…deformation signal been present in the data a smoother more confident subsidence pattern would almost certainly have been observed, as was present in previous studies of spatially correlated motion using the technique (Bateson et al, 2015;Sowter et al, 2013;Sowter et al, 2016). and fig.…”

“…Results have greatly increased the density of measurements over regions largely dominated by rural land cover, leading to a more consistent overall coverage and a more confident interpretation. It has been used to determine surface movements in various application areas including; coal extraction in the UK (Sowter et al, 2013, Novellino et al, 2014a, Bateson et al, 2015, landslips in Italy (Novellino et al, 2014b), elevation changes associated with blanket peat in Wales (Cigna et al, 2014) and groundwater abstraction in Mexico (Sowter et al, 2016).…”

25 years of satellite InSAR monitoring of ground instability and coastal geohazards in the archaeological site of Capo Colonna, Italy

“…Finally, Sentinel-1A ascending mode images acquired between October 2014 and May 2016 (Table 1) and made available via the Sentinel Scientific Data Hub [27] were processed using an improved version of the ISBAS technique [25][26]. To create the small baseline interferograms a threshold of one-year temporal baseline was used, while values of the perpendicular baseline were all below 200 m, hence complying with the common threshold used in SBAS processing.…”

Long-Term Peatland Condition Assessment via Surface Motion Monitoring Using the ISBAS DInSAR Technique over the Flow Country, Scotland

“…Furthermore, this issue is particularly challenging when using C-band SAR data. The novel Intermittent Small Baseline Subset (ISBAS) method [40], which is related to the SBAS technique described by [41], permits pixels of variable coherence to be considered alongside those with consistently high coherence [42][43][44]. Over a range of land covers, it has been demonstrated that the ISBAS method provides up to 26 times more coverage than SBAS [45].…”