User Help

This Bathymetry Viewing and Download service provides bathymetric data products for the geo-professional. It assumes that the user has a basic familiarity with geo-spatial tools and terminology.

The EMODnet digital terrain model (DTM), on which all products in this service are based, has been created at a resolution of 0.125 arc-minutes using the best available bathymetry from a variety of sources. There are still a lot of areas where no high quality bathymetry is available. To prevent gaps in the EMODnet DTM layer, these areas have been filled with the GEBCO 2014 data.

Disclaimer:

Although the bathymetry available is based on the best available bathymetry and every effort is made with respect to the quality assurance and quality control, it should be noted that, accuracy, completeness, reliability, usability or suitability of the bathymetry cannot be guaranteed. Therefore the data products available from this service are not to be used for navigation or for any other purpose relating to safety at sea. EMODnet assumes no responsibility for incorrect results or damages resulting from the use of the data.

Browser support is given from Firefox 35, Chrome 40, IE 11, all under Windows 7 and 8, and Safari 7.1, Firefox 35, Chrome 40 under OS X. Older browsers might experience problems due to the used technologies.

Table of Contents

What the Bathymetry Viewing and Download service provides

This service provides bathymetric data products for the area specified by the EMODNet project. This covers the Norwegian Sea, Icelandic Sea, Celtic Seas, North Sea, Kattegat, Baltic Sea, English Channel, Bay of Biscay, Iberian Coast, West and Central Mediterranean, Adriatic Sea, Ionian Sea, Aegean Sea, Levantine Sea, Sea of Marmara, Black Sea, the Azores, Canary Islands and Madeira. The data product is provided in one eight arc minute grid, so data points are roughly 230 meters apart.

The bathymetric data product can be downloaded in different formats. Currently the following formats are supported: native EMODnet csv, ASCII xyz, Esri ASCII grid, EMODnet NetCDF, GeoTIFF and QPS SD (Fledermaus). The EMODnet csv and NetCDF files are available with and without GEBCO and interpolated (INT) values. The download is divided over 16 tiles. Apart from downloading bathymetric data products the service provides information regarding point depth, transects and meta data of the underlying surveys. The survey data itself are not directly available but the related EMODnet Bathymetry CDI Data Discovery and Access service provides facilities for identifying and requesting access to survey data sets. The EMODnet bathymetric data product is based on survey data and composite digital terrain models of hydrographic organizations and research institutes (a complete overview of the contributing organizations and partners can be found at the EMODnet bathymetry website). There are areas that are not covered by these surveys or composite DTM's. These areas have been filled with data available from GEBCO 2014.

The Bathymetry Viewing and Download service also provides a source references layer with metadata for the detailed survey data and composite DTM's as used for the EMODnet bathymetry data product.

Bathymetry viewing and download service interface


Using the service

Using the service will address the layer panel, adding a layer yourself and using the available tools in the user interface.

Use interface layout

The service provides essentially a bathymetric map. There are several layers and these layers, when activated, can have specific functions which are displayed in the top bar by buttons.

Layers panel

The layers panel is the main control for choosing what kind of information you would like to examine. Although many layers can be made visible at the same time, only one layer can be active. The active layer determines the behaviour and corresponding functionality. The layer list can be selected by clicking on the down arrow of the left selection list in the function bar. Every layer has the following properties:

Layers panel

Adding a layer

In addition to the available layers you can add layers yourself. Click on Add layer to initiate the process of adding a WMS layer. Complete the following steps:

Make sure the added layer is based on WGS84. WMS Layers based on projections are not supported.

Using the general tools

The following tools are available:

Then depending on the active layer additional tools and functions will be available. These tools and functions will be explained below in the context of specific layers.

Continuing from the last session

If your browser supports HTML5 storage the user defined WMS layer(s) and predefined WMS layer settings as well as the zoom level and pan position are stored. When starting a new session the portal will be initialized with these settings. When a browser option like clearing session data when closing a tab or browser is active, the session settings are lost.


Using the Data product

The Bathymetric data product

The EMODnet data products are based on the continuous average depth grid of one eight arc-minute. This grid is based on two source types: Individual bathymetric surveys and composite digital terrain data (cDTM). The latter has been used whenever the actual survey data was unavailable for direct processing by the EMODnet partners. Whenever survey data and cDTM data were unavailable GEBCO data has been used to fill in the gaps.

Different layers of bathymetric data are available:

The following information can be retrieved from the active depth layers by additional function buttons:


The Source references layer

This layer depicts the most significant elementary surface used for generating the grid cell value. The minimum resolution for this layer is 5 EMODnet grid cells in order to prevent to much detail in this layer. For every 5 EMODnet grid cells the most significant elementary surface has been determined. All neighbouring source reference "points" with the same reference are represented by a single polygon. Every polygon has its own fill colour. All polygons referencing the same source have the same fill colour. Be aware that one colour is not referencing the same unique source, since this would require more than 6.000 different colours. The only exception is that a grey fill colour always references a GEBCO source.

Source reference


The Survey tracks / polygons layer

This layer is provided as WMS by the EMODnet Bathymetry CDI Data Discovery and Access service. It shows all survey tracks and polygons for which survey data is available in the service, and not only those that have been used for the EMODnet Bathymetry data product. Also this has a global coverage.

Survey tracks


Download products

Download products tool

The Download products button is always visible and allows you to select and download EMODnet Bathymetry DTM tiles in various formats. Clicking on the button will display a grid of 16 tiles over the EMODnet Bathymetry area. Then clicking on one tile will open a pop-up window with a selection of download file types: EMODnet CSV, EMODnet NetCDF, both including the EMODnet data model and with or without GEBCO and interpolated (INT) gridcells, ESRI ASCII, GeoTiff, Fledermaus SD, and XYZ files.

The file types have the following specifications:


Personal Layer

(NOTE: The service is at present being revised and not available.)

The Personal Layer offers registered users the ability to add their own data to the EMODnet portal. Data can be uploaded and visualised in a personal layer against the EMODnet data. Therefore user supplied high density data (multi-beam data) will be converted at the portal to the native EMODnet grid format with 1/8 arc minute resolution and thereafter be made available in a Personal Layer in the Layer Menu for viewing.

For 'login' users must be registered in the SeaDataNet User Register.

After registering and logging in to the portal, two additional layers will appear in the drop down layer panel: A Personal Layer Source Reference and a Personal Layer DTM. Note that it may take some time to prepare the layers on the server.

The source reference layer will show the individual surveys as they are added to the Personal Layer. The DTM layer shows the resulting deconflicted DTM. The DTM uses a relative colour schema which differentiates it from the EMODnet layers.

Personal layer source reference

By using a different colour schema also data in relatively shallow water can be visualised clearly.

After activating the Personal Layer DTM layer, 4 additional buttons become available at the top of the screen: Retrieve depth, Depth profile, Download Esri grid and Download GeoTIFF. These functions operate on the data of the Personal Layer and have no interaction with the EMODnet layers.

Personal layer dtm

Uploading new data

Before anything can be done with the Personal Layer, background data must be uploaded to the server. This is done by using the Import Data button that appears after login in. The button can be found next to the feedback button at the top of the screen. The button activates the Import screen:

Import survey

Select a local data file and upload it to the server. The file must comply to the Personal Layer specifications:

Example:

3.67714259 51.43614336 20.26
3.67714074 51.43615053 20.45
3.67713604 51.43615702 20.55
3.67713505 51.43616412 20.59
3.67713408 51.43617111 20.58
3.67713066 51.43617798 20.32
3.67712715 51.43618332 20.19
3.67712393 51.43619208 20.12
etc.

The list with metadata fields is only intended to demonstrate the capabilities of the Personal Layer. The list can be extendended or modified in later versions of the portal. Only the Name, Survey start date en quality are mandatory. Note that CDI references must be valid entries. The reference is used to search for metadata in the CDI Data Discovery and Access service.

After uploading (high density) background survey data, the EMODnet Server processes the data. This may take some time depending on the size of the dataset. A coverage polygon is automatically generated for each file that is uploaded. Based on survey date and quality the survey is added to the Personal Layer DTM. Higher quality surveys have preference over lower quality. The survey start date is used in case of equal quality.

The status of the upload and processing process can be monitored in the status window that appears after the upload screen is closed.

Import status

The status screen shows the current task and its status. An hourglass icon indicates that the server is processing the new upload. Previous uploads are also shown on the status screen.

By selecting "Return to map" the result can be visualised.

Example of personal layer dtm

Example of a personal Layer DTM agains a single colour EMODnet background


WMS services

The EMODnet Bathymetry layers are also available as OGC compliant web services:

WMS:http://ows.emodnet-bathymetry.eu/wms
WFS:http://ows.emodnet-bathymetry.eu/wfs
WMST:http://ows.emodnet-bathymetry.eu/wmts

Colophon

In addition to the data and products of EMODnet bathymetry partners use is made of the following sources:


Questions & Feedback

For questions and feedback please use the Feedback button of the portal. We would really like to know your findings and ideas on how the portal could be improved.


Configuration information

This help text is version 2.0 and released on 5 February 2015.

The Bathymetry Viewing and Download service is built and maintained by GGSgc and partners coordinated by MARIS and on behalf of the European Commission.