caca9b7d93a878f27e5a011edc09a577 English dataset Suzana EL Massri MMT Sweden AB suzana.el-massri@mmt.se pointOfContact Cajsa Hermansson MMT Sweden AB cajsa.hermansson@mmt.se pointOfContact Jacob Laken MMT Sweden AB jacob.laken@mmt.se pointOfContact 2022-03-24 MEDIN Discovery metadata standard 2.3.8 urn:ogc:def:crs:EPSG::32630 2022 MMT SSE Kyntire SSS 2022-03-31 publication 103963-MMT-SSS Scottish Hydro Electric Transmission Plc (SHET) have awarded MMT the inspection survey of operational HVAC Subsea Cables between Kintyre and Hunterston in West Scotland. The inspection survey covered two operational HVAC cables, referred to as North Circuit Route (NCR) and South Circuit Route (SCR), the routes are 40.982 km and 40.518 km long respectively and are approximately parallel (Figure 1). Inspection operations were conducted within water depths equal to and more than 15m LAT with M/V Stril Explorer via a Work Class Remotely Operated Vehicle (WROV) mobilised with Multi Beam Echo Sounder (MBES), Side Scan Sonar (SSS), digital cameras and cable tracking systems. Horizontal datum WGS 84 and projection UTM 30 N, EPSG: 32630. MMT Sweden AB MMT Sweden AB MMT Sweden AB dassh.enquiries@mba.ac.uk originator MMT Sweden AB MMT Sweden AB MMT Sweden AB dassh.enquiries@mba.ac.uk custodian notPlanned Delimited Image Ocean Data View Marine Environmental Data and Information Network Geology Land cover GEMET - INSPIRE themes, version 1.0 2008-01-06 revision Side-scan sonar SeaDataNet P021 parameter discovery vocabulary 2009-11-16 revision Offshore Cables Offshore Cables 2015-10-19 creation Company owned data, not to be used otherRestrictions Company owned data, not to be used English geoscientificInformation imageryBaseMapsEarthCover Charting Progress 2 Sea Areas 2009-06-18 creation Scottish Continental Shelf International Hydrographic Bureau, Limits of Oceans and Seas 1954-01-01 creation Inner Seas off the West Coast of Scotland SeaDataNet vertical extent keywords 2010-01-01 revision bathybenthic -5.6180 -4.7227 55.5661 55.9002 2022-01-31 2022-02-10 MMT Sweden AB MMT Sweden AB MMT Sweden AB dassh.enquiries@mba.ac.uk distributor dataset Side scan sonar data were collected using an EdgeTech 2205 mounted to a WROV with dual high/low frequency recording enabled. The data were recorded in .jsf format using the Discover software and the files were split at 600Mb.. The WROV maintained an altitude of 3 m above the seabed and a speed of 1-1.5kts. A range of 35m was aqcuired at dual 900 and 300kHz. The data was acquired in a single pass however in the end two passes were recorded in total. Overall only the first pass of data was processed however some data from the second pass has been used where small gaps are present in the initial pass. Of this data only the high frequency data was used. The data quality was generally good. The stability of the WROV was good reducing any motion induced artefacts in the data. Occasionally however, motion artefacts are present, particularly where the cable course deviates. The effect of this is “stretching” of data in the channel on the outside of the turn and compression of data in the inside channel. SonarWiz V7.08.01 was used to process the data by picking the water bottom and applying EGN gains and a nadir filter. Raw navigation was used and a smoothing filter of 60 pings was applied throughout the dataset. A static shift of 1.22m alongtrack was applied to the entire dataset. Corrected XTFs were exported directly from SonarWiz and mosaics were created.