4f4c4942-4343-5764-6473-313130303337 English Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2024-12-09T13:16:44.635Z NRW 1.0 wel British National Grid (EPSG::27700) Broadscale Remote Survey and Mapping of Sublittoral Habitats and Biota of Milford Haven, Pembrokeshire and South Cardigan Bay Broadscale Remote Survey and Mapping of Sublittoral Habitats and Biota of Milford Haven, Pembrokeshire and South Cardigan Bay Arolwg o bell a mapio graddfa eang cynefinoedd a biota isarforol Aberdaugleddau, Sir Benfro a de Bae Ceredigion 1999-12-31 NRW_DS110037 The Broadscale Mapping Project has been devised and funded by a consortium consisting of the Crown Estate, the Countryside Council for Wales, English Nature, Scottish Natural Heritage and the SeaMap research group based at Newcastle University and undertaken by SeaMap. Three trial areas were selected, around Milford Haven, Pembrokeshire and South Cardigan Bay, for developing and testing the methodology, although experience from many other surveys conducted by SeaMap have also contributed to the development of the methodology. The aim of this data collection was to map the seafloor sediments and biota, for habitats and biotope mapping. This was supplemented by maps and supporting data showing the location of ground truth samples and the positions of the acoustic tracks. The Broadscale Mapping Project has been devised and funded by a consortium consisting of the Crown Estate, the Countryside Council for Wales, English Nature, Scottish Natural Heritage and the SeaMap research group based at Newcastle University and undertaken by SeaMap. Three trial areas were selected, around Milford Haven, Pembrokeshire and South Cardigan Bay, for developing and testing the methodology, although experience from many other surveys conducted by SeaMap have also contributed to the development of the methodology. The aim of this data collection was to map the seafloor sediments and biota, for habitats and biotope mapping. This was supplemented by maps and supporting data showing the location of ground truth samples and the positions of the acoustic tracks. Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Newcastle University Newcastle upon Tyne, Tyne and Wear, Newcastle, NE1 7RU unknown http://www.ncl.ac.uk/ Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Environmental monitoring facilities Environmental monitoring facilities GEMET - INSPIRE themes, version 1.0 GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme mapping (map drawing) (cartography)(see also digital mapping) Milford Haven Pembrokeshire (county pre 1974)( county since 4/96) marine and freshwater inventory remote survey South Cardigan Bay sea floor acoustic remote sensing acoustic ground discrimination system digital images satellite images NRW Thesaurus NRW Thesaurus 2023-12-31 geonetwork.thesaurus.local.theme.converted_nrw-keywords Habitat characterisation SeaDataNet Parameter Discovery Vocabulary SeaDataNet Parameter Discovery Vocabulary 2021-01-06 geonetwork.thesaurus.external.theme.rdf+xml There are no access restrictions to this data. NRW may release, publish or disseminate it freely. no limitations © CNC/NRW 1999. There are no use restrictions on this data. Recipients may re-use, reproduce, disseminate this data free of charge in any format or medium, provided they do so accurately, acknowledging both the source and NRW's copyright, and do not use it in a misleading context. It is the recipient's responsibility to ensure the data is fit for the intended purpose, that dissemination or publishing does not result in duplication, and that it is fairly interpreted. Advice on interpretation should be sought where required. To avoid re-using old data, users should periodically obtain the latest version from the original source. English oceans biota SeaVoX Vertical Co-ordinate Coverages SeaVoX Vertical Co-ordinate Coverages 2021-01-06 benthic boundary layer Wales (WLS) -5.46850994 -4.02399813 51.43965144 52.61247764 1994-01-01 1998-12-31 Broad scale remote survey and mapping of sublittoral habitats and biota of the Milford Haven, Pembrokeshire and South Cardigan Bay Geographic Information System [A] Report (MS Word [B] GIS Data (Mapinfo native and Idrisi format files) [C] Image Data (3D topographic models .jpg) [D] Spreadsheet Data (MS Excel) Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 false Image processing requires ground truth samples of the biota and habitats from the sea floor and the sampling techniques range from the traditional grab, trawl and dredge to the deployment of remote video. The video is especially useful since it provides a vista of the sea floor which is approximately of the same extent as the area of the seafloor that is covered by one pulse from an echo sounder (the 'footprint'). Image processing is a two-stage process: In the first stage the acoustic data in the immediate vicinity of the ground truth positions are selected and tagged according to the type of habitat or biotope of the ground truth sample. The acoustic data are pooled for each habitat or biotope type and the acoustic characteristic calculated from the mean and standard deviation of the depth and the hardness and roughness values. In this way an acoustic signature is created for each habitat or biotope type. In the second stage each pixel is matched to the signatures and the likelihood of the pixel belonging to each habitat or biotope calculated. An automated process then selects the most likely category for the pixel. This second stage is, therefore, called a maximum likelihood classification. The methodology relies on the relatively inexpensive acoustic ground discrimination system (AGDS) based on a single beam echo sounder. AGDS analyse the echo from the sounder and gives a measure of the hardness and roughness of the sea floor, as well as depth. These records, in the form of point data, are logged together with time and position as the vessel tracks over the survey area. The point data are used to create continuous digital images for each of the variables through interpolation. This conversion to digital images consisting of rows and columns of pixels enables powerful image processing software, designed primarily for the processing of satellite images, to be applied to the acoustic data. Image processing requires ground truth samples of the biota and habitats from the sea floor and the sampling techniques range from the traditional grab, trawl and dredge to the deployment of remote video. The video is especially useful since it provides a vista of the sea floor which is approximately of the same extent as the area of the seafloor that is covered by one pulse from an echo sounder (the 'footprint'). Image processing is a two-stage process: In the first stage the acoustic data in the immediate vicinity of the ground truth positions are selected and tagged according to the type of habitat or biotope of the ground truth sample. The acoustic data are pooled for each habitat or biotope type and the acoustic characteristic calculated from the mean and standard deviation of the depth and the hardness and roughness values. In this way an acoustic signature is created for each habitat or biotope type. In the second stage each pixel is matched to the signatures and the likelihood of the pixel belonging to each habitat or biotope calculated. An automated process then selects the most likely category for the pixel. This second stage is, therefore, called a maximum likelihood classification. The methodology relies on the relatively inexpensive acoustic ground discrimination system (AGDS) based on a single beam echo sounder. AGDS analyse the echo from the sounder and gives a measure of the hardness and roughness of the sea floor, as well as depth. These records, in the form of point data, are logged together with time and position as the vessel tracks over the survey area. The point data are used to create continuous digital images for each of the variables through interpolation. This conversion to digital images consisting of rows and columns of pixels enables powerful image processing software, designed primarily for the processing of satellite images, to be applied to the acoustic data.