Time-series displacement from high-resolution satellite Synthetic Aperture Radar (SAR) data using Sub-Pixel Offset Tracking (SPOT)

Time-series displacements at Merapi volcano, Indonesia, from high-resolution SAR and sub-pixel offset tracking (SPOT). When using this dataset, please cite the authors: Bemelmans, Mark^1,2,+; Biggs, Juliet^1,2; Wookey, James^1; Poland, Michael^3. 1: School of Earth Sciences, University of Bristol, Bristol, United Kingdom.2: Centre for the Observation and Modelling of Volcanoes, Earthquakes, and Tectonics (COMET), United Kingdom.3: Cascades Volcano Observatory (CVO), U.S. Geological Survey (USGS), Vancouver, Washington, The United States.+: corresponding author, mark.bemelmans@bristol.ac.uk *Work is currently in preparation and will be updated when publication information is known.* Background Information: Synthetic Aperture Radar (SAR) data are collected through the Centre for Earth Observation Satellites (CEOS). The COSMO-Skymed (CSK) data are owned by the Italian Space Agency (ISO) and the TerraSAR-X (TSX) data are owned by the Deutsche Lüft- und Raumfarht Centrum (DLR). Additionally, the Digital Elevation Model (DEM) used to correct for parallax shift is from Thomas and Darmawan, 2021. (High-resolution Digital Elevation Model of Merapi summit in 2015 generated by UAVs and TLS and TanDEM-X. The data are processed using GAMMA-rs (Werner et al., 2000) using Sub-Pixel Offset Tracking (SPOT). SPOT uses image cross-correlation of small image patches to extract displacements (offsets) to sub-pixel precision. Details of the data processing can be found in [Bemelmans et al., in prep] This data set currently includes data from CSK (heading 168 deg., incidence angel 35.6 deg., image resolution 0.34 in slant range, 0.70 in azimuth) with the following dates: 20200910202009192020092620200927202010052020101220201013202011132020111420201122202012242020123120210101202101092021011620210117202101252021020120210202202102172021021820210302202103052021030620210314202103212021032220210330202104062021041920210422202104232021050120210508202105092021052120210609202107112021072020210727202107282021081220210813202108292021091020210913202109142021092220210926202109302021101520211016202110242021103120211101 We also have data from TSX (heading 191 deg., incidence angle 37.6 deg., image resolution 0.45 m in slant range, 0.17 m in azimuth). We have acquisitions from the following dates: 202011162020112720201208202012192021011020210201202102232021031720210408202104302021052220210602202106132021100120211023 For each acquisition we process pixel offsets to the 3 adjacent ac