a0227223c0211430027e5beac4550fc6 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_Magnetometer_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 magnetometer 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 Magnetics 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 Vessel: MV Bibby Tethra Equipment: Geometrics G882 Software: Oasis Montaj, ArcGIS Positional uncertainty: ± 2.0m Contact Listing Oasis Montaj was used to identify mag contacts equal to or greater than 5nT. Bathymetry and SSS mosaics were used to aid interpretation of targets and determine their confidence interval according to the levels defined in the scope of work. Trackplots Navigation was manually de-spiked; smoothed applying a non-linear filter (width 150) and interpolated through a maxiumum of 5 seconds. The altitude data was put through the same process (filter width 5). Trackplots were processed and exported in Geosoft Oasis Montaj version 9.4.3 Grids Anomalous spikes in navigation were removed and a Non-linear filter was applied with a filter width of 150 and a tolerance of 0.0001. Navigation was then interpolated with a maximum interpolation gap of 50 fiducials. Grid resolution is 0.5m Grid Parameters Resiudal Grid: Minimum Curvature grid (cell size = 0.5m, blanking distance = 20m), Geosoftâ??s standard colour tool bar with normal distribution. Parameters: mean = 0, SD = 60, expansion = 0.05. Data clipped to accepted altitude values (0.0-4m) Total Field Grid: Minimum Curvature grid (cell size = 0.5m, blanking distance = 20m), Geosoftâ??s standard colour tool bar with normal distribution. Parameters: mean = 49350, SD = 50, expansion = 1. Data clipped to accepted altitude values (0.0-4m) Altitude Grid: Direct gridding of the processed altitude values (cell size = 0.5m), colour scale: >5m red, 4.5-5m orange, 4-4.5m yellow, 1-4m green, 0-1m blue Signal Strength Grid: Direct gridding of the Signal Strength values (cell size = 0.5m), geosoftâ??s standard colour tool bar with normal distribution. Parameters: mean = 650, SD = 350, expansion = 1