LiCSAR: An Automatic InSAR Tool for Measuring and Monitoring Tectonic and Volcanic Activity

Abstract

Space-borne Synthetic Aperture Radar (SAR) Interferometry (InSAR) is now a key geophysical tool for surface deformation studies. The European Commission’s Sentinel-1 Constellation began acquiring data systematically in late 2014. The data, which are free and open access, have global coverage at moderate resolution with a 6 or 12-day revisit, enabling researchers to investigate large-scale surface deformation systematically through time. However, full exploitation of the potential of Sentinel-1 requires specific processing approaches as well as the efficient use of modern computing and data storage facilities. Here we present LiCSAR, an operational system built for large-scale interferometric processing of Sentinel-1 data. LiCSAR is designed to automatically produce geocoded wrapped and unwrapped interferograms and coherence estimates, for large regions, at 0.001° resolution (WGS-84 system). The products are continuously updated in a frequency depending on prioritised regions (monthly, weekly or live update strategy). The products are open and freely accessible and downloadable through an online portal. We describe the algorithms, processing, and storage solutions implemented in LiCSAR, and show several case studies that use LiCSAR products to measure tectonic and volcanic deformation. We aim to accelerate the uptake of InSAR data by researchers as well as non-expert users by mass producing interferograms and derived products.

Magmatic Processes in the East African Rift System: Insights From a 2015–2020 Sentinel‐1 InSAR Survey

“…We process Sentinel-1 SAR data from 13 frames covering the EARS (Supplementary Material Table S1) for a 5-year period between October 2014 and December 2019, using the LïCSAR processing system (Lazeckỳ et al, 2020). LïCSAR is built on the GAMMA software package (Werner et al, 2000) and automatically generates the three shortest temporal baseline interferograms for each acquisition at a spatial resolution of 0.001° × 0.001° (∼111 m at the equator).…”

“…Here, we systematically report results from the first 5 years of Sentinel-1 data along the East African Rift System. Using the LïCSAR automated system (Lazeckỳ et al, 2020), we process about 4,000 interferograms along the EARS with a large majority (∼85%) generated from descending tracks (Supplementary Material Table S1). In total, we produce Sentinel-1 InSAR time series over 64 Holocene active volcanoes between October 2014 and January 2020 (Albino & Biggs, 2021) (Supplementary Material Tables S2-S4).…”

Baseline monitoring of volcanic regions with little recent activity: application of Sentinel-1 InSAR to Turkish volcanoes

“…Lack of expertise is often cited as a barrier to the uptake of satellite technology and several capacity building efforts are ongoing to address this issue. An alternative is to develop automated systems that require little user input (Meyer et al 2015;Lazecky et al 2020). Here we consider two approaches that are particularly suited to regions with little record of volcano deformation who wish to use satellite data for baseline monitoring (i.e.…”

“…Since the launch of Sentinel-1B in 2017, the revisit time has reduced to 6 days. The data is freely available from the European Space Agency, automatically processed by the LiCSAR system described in Lazecky et al (2020) and made available online at https://comet.nerc.ac.uk/COMET-LiCS-portal/ . The Turkish Volcanoes can be covered using 7 frames of ascending data and 7 frames of descending data (Table 1).…”

Improved rapid landslide detection from integration of empirical models and satellite radar

“…It is for this reason that we employed two tracks of Sentinel-1 data, but this is currently not often available for Lband SAR. We processed the SAR data using GAMMA software, with Sentinel-1 data processed using the LiCSAR package (Lazeckỳ et al, 2020). The data were processed in a Range × Azimuth coordinate system and then projected into a geographic coordinate system with a spatial resolution of 20 m × 22 m. Further details on parameter choices made in the generation of the CECL, Bx-S, PECI, ∆C_sum and ∆C_max surfaces can be found in Burrows et al (2020).…”