A geodetic survey was used to provide ground control points for the structure from motion surveys. Black and white checked mats placed on the ground were used for the ground control points and these are visible in the structure from motion imagery. Ground control points were collected from the proximal Skeiðarársandur area (~63.9 N, 17.2 E) on the 15th to 17th April and 19th April 2022. Ground control points were collected at the Skeiðarársandur coastline (63.7 N, 17.5 E) that lie at the mouth of Gígjukvísl on 18th April 2022. In total 46 ground control points were collected providing the latitude and longitude (WGS84) of each point. The GNSS (Global Navigation Satellite System) data were collected using a Leica GS14 rover and base station. The rover was placed on an antenna . Antenna height was measured for each survey. The Antenna height for the rovers on 15th April-17th April, 18th April part 2 and 19th April were 2 m. The antenna height on 18th April part 1 was 0.00m. Latitude, longitude (WGS84) and elevation data was collected at each ground control point. This data was used to provide spatial control for the structure from motion survey. GNSS data was also collected during the geophysical surveys that were carried out in 11-24th June 2022. These surveys included the side-scan sonar and CHIRP data collected in a proglacial lake fronting Skeiðarárjökull and used to georeferenced the survey data. The base station data and rover data was post-processed against a permanent GNSS station located at Fagurhólsmýri (63° 52' 28.84" N 16° 39' 11.87" W) maintained by the IMO. Corrected data is used to update and shift RTK GNSS observations. This data was collected by staff at Newcastle University in the School of Geography, Politics and Sociology. File format of raw data is M00 the processed data is in a text document, as pdf and ascii files.
