Catalogue PIGMA
EMODnet Human Activities, Vessel Density Map
The Vessel Density maps in the EU were created in 2019 by Cogea for the European Marine Observation and Data Network (EMODnet). The dataset is updated every year and is available for viewing and download on EMODnet Human Activities web portal (www.emodnet-humanactivities.eu). The maps are based on AIS data yearly purchased from Collecte Localisation Satellites (CLS) and ORBCOMM. The maps, GeoTIFF format, show shipping density in 1x1km cells of a grid covering all EU waters and some neighbouring areas. Density is expressed as hours per square kilometre per month. The following ship types are available:0 Other, 1 Fishing, 2 Service, 3 Dredging or underwater ops, 4 Sailing, 5 Pleasure Craft, 6 High speed craft, 7 Tug and towing, 8 Passenger, 9 Cargo, 10 Tanker, 11 Military and Law Enforcement, 12 Unknown and All ship types. Data are available by month of year. Yearly averages are also available.
Simple
- Date (Publication)
- 2019-03-11
- Date (Revision)
- 2021-03-25
- Date (Creation)
- 2019-03-11
- Identifier
- EMODnet_HA_Vessel_Density_20191216
- Credit
- European Marine Observation and Data Network
- INSPIRE feature concept dictionary (Version: Linked Data 1.0)
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- Marine Layer
- Marine Waterway
- Transport Area
- GEMET (version 3.1, 2012-07-20)
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- merchant shipping
- maritime navigation
- maritime transport
- GEMET - INSPIRE themes, version 1.0
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- Transport networks
- Geographical grid systems
- Mission Atlantic - Resources
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- Data
- Mission Atlantic - BODC Parameters
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- /Human activities/Transport
- Mission Atlantic - Work Package
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- WP3 Pelagic Mapping
- Mission Atlantic - Case Studies
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- Celtic Seas
- North Mid-Atlantic Ridge
- Mission Atlantic - Data type (DMP)
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- Spatial data products
- Use limitation
- Re-use of content for commercial or non-commercial purposes is permitted free of charge, provided that the sources (both EMODnet - Human Activities, and CLS) are acknowledged. EMODnet - Human Activities accepts no responsibility or liability whatsoever for the re-use of content accessible on its website.
- Access constraints
- Other restrictions
- Other constraints
- no limitation
- Spatial representation type
- Grid
- Distance
- 1000 metre
- Metadata language
- EnglishEnglish
- Topic category
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- Oceans
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))
- Begin date
- 2017-01-01
- End date
- 2018-12-31
- Reference system identifier
- EPSG:3035
- Reference system identifier
- ISO 19108 calendar
- Distribution format
-
-
TIFF
(
6.0
)
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TIFF
(
6.0
)
- Transfer size
- 0
- OnLine resource
-
EMODnet Human Activities
(
WWW:LINK
)
EMODnet Human Activities aims to facilitate access to existing marine data on activities carried out in EU waters, by building a single entry point for geographic information on human uses of the ocean. The portal makes available information such as geographical position, spatial extent of a series of activities related to the sea, their temporal variation, time when data was provided, and attributes to indicate the intensity of each activity. The data are aggregated and presented so as to preserve personal privacy and commercially-sensitive information. The data also include a time interval so that historic as well as current activities can be included.
- OnLine resource
- Access data ( WWW:LINK )
- Hierarchy level
- Dataset
Conformance result
- Date (Publication)
- 2008-12-04
- Explanation
- See the referenced specification
- Pass
- Yes
Conformance result
- Date (Publication)
- 2009-12-15
- Explanation
- See the referenced specification
Conformance result
- Date (Publication)
- 2010-12-08
- Explanation
- See the referenced specification
- Pass
- Yes
- Statement
- AIS data are annualy purchased from two commercial providers, CLS and ORBCOMM. The data consists of messages sent by automatic tracking systems installed on board ships and received by terrestrial and satellite receivers alike. The acquired datasets currently cover a period from 2017 to 2020 for an area covering all EU waters. A partial pre-processing of the data is carried out by CLS: (i) The only AIS messages delivered are the ones relevant for assessing shipping activities (AIS messages 1, 2, 3, 18 and 19). (ii) The AIS data are down-sampled to 3 minutes (iii). Duplicate signals are removed. (iv) Wrong MMSI signals are removed. (v) Special characters and diacritics are removed. (vi) Signals with erroneous speed over ground (SOG) are removed (negative values or more than 80 knots). (vii) Signals with erroneous course over ground (COG) are removed (negative values or more than 360 degrees). (viii) A Kalman filter is applied to remove satellite noise. The Kalman filter is based on a correlated random walk fine-tuned for ship behaviour. The consistency of a new observation with the modelised position is checked compared to key performance indicators such as innovation, likelihood and speed. (ix) A footprint filter is applied to check for satellite AIS data consistency. All positions which are not compliant with the ship-satellite co-visibility are flagged as invalid. The AIS data are converted from their original format (NMEA) to CSV, and deliverd to Cogea split into 12 files, each corresponding to a month of the year. By running a series of commands from Linux shell, all remaining invalid characters are removed as well as unnecessary fields. The data are then imported into a PostgreSQL relational database (with the PostGIS extension), each month in a different table containing the following specialised data types: mmsi (numeric), locdate (date), loctime (time without time zone), lon (double precision), lat (double precision), aisshiptype (character varying). MMSI numbers are often associated to more than a ship type during a year. To cope with this issue, a unique MMSI/ship type register is created every year. In the register, MMSI with multiple ship types are associated the most recurring ship type by counting the number of record for each combination mmsi/ship type. The admissible ship types reported in the AIS messages are grouped into macrocategories: 0 Other, 1 Fishing, 2 Service, 3 Dredging or underwater ops, 4 Sailing, 5 Pleasure Craft, 6 High speed craft, 7 Tug and towing, 8 Passenger, 9 Cargo, 10 Tanker, 11 Military and Law Enforcement, 12 Unknown and All ship types. The subsequent steps consist of creating points representing ship positions from the AIS messages, then reconstructing ship routes (lines) from the points for every two consecutive positions of a ship, by using the MMSI number as a unique identifier of a ship. In addition, for each line the query calculates its length (in km) and its duration (in hours) and append them both as attributes to the line. If the distance between two consecutive positions of a ship is longer than 30 km or if the time interval is longer than 6 hours, no line is created. Both datasets (points and lines) are projected into the ETRS89/ETRS-LAEA coordinate reference system, used for statistical mapping at all scales, where true area representation is required (EPSG: 3035). Points and lines calculations are based on custom-made sql scripts developed by Cogea. The lines obtained are then intersected with a custom-made 1x1km grid polygon (21 million cells) created by Cogea, based on the EEA's national grids, extended to cover the whole area of interest (all EU sea basins) and imported in PostGIS. Because each line has length and duration as attributes, it is possible to calculate how much time each ship spent in a given cell over a month by intersecting line records with grid cell records. This is done through a custom-made sql script developed by Lovell Johns. Using the PostGIS Intersect tool, for each cell of the grid, the time value of each 'segment' in it is summed, thus obtaining the density value associated to that cell, stored in calculated PostGIS tables. Density is thus expressed in hours per square kilometre per month. The final step consists of creating and compressing raster files (TIFF file format) with QGIS and GDAL from the PostGIS vessel density tables. Annual average rasters by ship type are also finally calculated. For more details on vessel density concepts see the full method published at: https://www.emodnet-humanactivities.eu/documents/Vessel%20density%20maps_method_v1.5.pdf. Comparared with the original method's calculations, from the 2021 (2020 data) the calculations of ship positions (points) and ship routes (lines) were sped up by moving them from ArcGIS to PostGIS.
Overviews
Spatial extent
N
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E
W
Provided by
Associated resources
Not available