3be637a9c6f04d87c4a4003371fe47f1 English dataset Ben Smith Bibby HydroMap Ltd CAD/GIS Technician Ben.Smith@bibbyhydromap.com pointOfContact 2018-11-27 MEDIN Discovery metadata standard 2.3.8 urn:ogc:def:crs:EPSG::25831 2018_023_HOW03_Lot8_Sample_B01_SBP_data 2018-11-16 publication 2018_023 Bibby HydroMap were commissioned in May 2018 by Orsted to carry out Geophysical and Benthic surveys at Horsea 03 Lots 5 and 8. The survey across the Lot 8 export route was completed under Bibby HydroMap's terms and conditions using MV Bibby Tethra, between 16th August and 3rd September 2018 with a 40m line spacing. The main objectives of the surveys were as follows: â?¢ Cable route engineering â?¢ Geo-hazard assessment â?¢ Consenting requirements o Identifying archaeological restrictions o Identifying protected ecological habitats â?¢ Planning of Geotechnical investigations â?¢ UXO clearance for Geotechnical investigations This dataset comprises of the subbottom data across the survey area. Theo Gaussen Bibby HydroMap Ltd Senior Geophysicist dassh.enquiries@mba.ac.uk originator Theo Gaussen Bibby HydroMap Ltd Senior Geophysicist dassh.enquiries@mba.ac.uk custodian notPlanned Geographic Information System Marine Environmental Data and Information Network Geology GEMET - INSPIRE themes, version 1.0 2008-01-06 revision Seismic reflection SeaDataNet P021 parameter discovery vocabulary 2009-11-16 revision Not suitable for use in navigation otherRestrictions Not for public distribution English geoscientificInformation 0.7557 1.1402 52.9341 53.1619 2018-08-16 2018-09-03 Theo Gaussen Bibby HydroMap Ltd Senior Geophysicist dassh.enquiries@mba.ac.uk distributor dataset Vertical Datum: BLAST LAT Horizontal Datum: ETRS89 Projected co-ordinate system: ETRS89 UTM Zone 31 North Transformation: from WGS84 to ETRS89 using 7-parameter Helmert at epoch 2018.7 Vessel: MV Bibby Tethra Equipment: Innomar SES-2000 Medium, iXBlue Hydrins INS, C-Nav integrated with Hydrins INS data Software: RadExPro, IHS Kingdom software, RUSH, In-house scripts in Python, QPS QINSy, Positional uncertainty: 0.15m (horizontal); 0.2m (vertical) Horizontal resolution: 0.20m Vertical resolution: 0.09m Ping rate: 11pps Central frequency: 10KHz Pulse cycles: 1 pulse Recording range: Variable recorded trace length 55.332, 62.004 and 68.664 ms; set to 72.000ms for vertical correction to Datum, to prevent cutting off unwanted record during vertical correction. Raw SEGY: SBP data acquired using Innomar acquisition system as SES and RAW format. Hydrins WGS84 positioning and time stamp with no latency and motion correction embedded online in Trace Header data. Raw SEG-Y files exported using SES-Convert. Positioning in ETRS89 UTM31N exported from QINSy offline (to remove latency), corrected for any navigation drop outs using in-house scripts in Python to be subsequently embedded in the SEG-Y Trace Headers by time stamp. Processed SEGY-Y: Processed SEG-Y files with calculated navigation, motion correction and tidal reduction from QINSY output for every ping. Vertical correction to Datum carried in RadExPro software from; no processing (filters, gains, etc) applied. SEG-Y data in two way travel time. Final data exported fromRadExPro and QC'ed in IHS Kingdom software. Small percentage of files with a static shift of 0.2ms applied in RADEXPRO Navigation QINSy calculated position, computed for Innomar node using C-Nav with the C-NavC2 correction service and iXBlue Hydrins INS data; Logfiles exported offline (to remove latency) from QPS QINSy navigation software at 1Hz. Any nav drop outs were removed and positions interpolated using in-house scripts in Python. Tide Correction File Logfiles exported online from Qinsy navigation software at 1Hz including Innomar sensor GNSS height and sound velocity from mini-SVS adjacent to MBES transducer. Polynomial smoothing applied to reduced GNSS heights using MatLAB scripted software RUSH. Smoothed reduced height converted to time using logged Mini-SVS sound velocities. GNSS height files per day. Extra fields included - smoothed sensor height, speed of sound at the MBES transducer and smoothed sensor height in milliseconds (microsecond accuracy); Tide File Format: Date, Hours, Min, Seconds, Raw GNSS Height, SV, Smoothed GNSS Height, Time delay (ms). Motion Correction Logfiles exported online from QPS QINSy navigation software at 1Hz (before being set up to 25Hz) including heave, pitch and roll at Innomar node. Trackplots QINSy 1Hz navigation logfiles interpolated for every sub-bottom data trace and applied to SEG-Y data using in-house scripts in Python (any nav drop outs were removed and positions interpolated). Positioning exported from SEG-Y Trace Header files using RADEXPRO software at sensor ping rate. Trackplot line and point generation in ArcGIS. using in-house scripts in Python. Point shp decimation - points every 200 pings, including ping at start of line Line shp decimation - approx 10 points a second (all pings included).