Web Map Service 
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ZATHYMETRY 
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-MODnet 
ZATHYMETRY 
nF 2 ODOSTaNRy DE hp EUTOPEAN SEA 
Rathymatıy Viranng and Deaumlaarl carvics 
ig. 1: Overview of the EMODnet bathymetry portal (https:/portal.emodnet-bathymetry.eu) showing the bathvmetric DTM » 
/16th arc minute resolution (left) along with the coverages of the source data (right) 
zor during the acquisition. Generally, HR-DTMs 
are covering areas of particular interests such as, 
for example, canyons, sea mounts, hydraulic sand 
dunes and coastal areas. For the North Sea, for ex 
ample, the German HR-DTMs are based in harmo- 
any with the DGM-W grids (Digitales Geländemo- 
dell des Wasserlaufs). These digital terrain models 
Yave been developed in cooperation between the 
aerman Waterways and Shipping Agencies and 
the German Federal Maritime and Hydrographic 
Agency. The DGM-W grids show the German es- 
tuaries of the Elbe, the Weser and the Ems with 
their individual bathymetric profile of tidal flats, 
inlets and shoals. These grids are a compilation of 
Multibeam echo sounder data, single-beam echo 
zounder data and LIDAR data. 
Describing source data is a key element for both 
the aggregation of individual data sources within 
the DTM and the interrogation and use of indi- 
vidual data by users through the data portal. Since 
the early stages of EMODnet Bathymetry, a strong 
relationship with the Pan-European SeaDataNet 
network and infrastructure has been established. 
SeaDataNet’s primary goal is the development 
af a standardised, distributed system for manag- 
iNg the large and diverse data sets collected by 
aceanographic fleets and automatic observation 
systems across various scientific themes. The key 
element in the realisation of such a distributed 
system includes common metadata standards for 
the expression of data ownership, data acquisi- 
tion and processing, communication and quality 
assurance. This includes the use of XML and inter 
national standards, such as ISO 19115 — 19139, and 
more imbportantiy shared (and commonlIv defined) 
AN 
117 — 10/2020 
/ocabularies. These are all managed in close col 
aboration between EMODnet Bathymetry, Sea- 
DataNet, OGC, ISO, W3C, within the definitions set 
2y the INSPIRE Directive 2007/2/EC. 
he benefits that EMODnet Bathymetry is get- 
King from this tight collaboration with SeaDataNet 
"eside in the explicit expression of lineage (origin), 
data quality, history and distribution conditions of 
he data sources. The SeaDataNet Common Data 
ndex (CDI) infrastructure and metadata standards 
‚with its network of distributed data centres have 
een adopted and adapted by EMODnet Bathym 
try to provide an integrated and harmonised 
overview and access to bathymetric surveys that 
are gathered by the project (Fig. 2). 
While the CDI is used as the basis for the descrip 
jon of individual bathymetric surveys, the EMOD 
ıet Bathymetry team is also conscious that some 
data providers want to provide gridded products 
zomposed from multiple sources, also known as 
zomposite grids. Hence, the EMODnet bathym- 
atry community has adopted and adapted the 
>eaDataNet Sextant catalogue service, in orde! 
“or data providers to provide details about Com- 
»osite DTMs. This is known as the CPRD index 
'CPRD stands for composite product). The Sextant 
netadata files also follow the ISO 19115 — 19139 
netadata standards and are supported by Sea 
JataNet controlled vocabularies. 
Underlying methodology and 
technology 
"MODnet Bathymetry deals with heterogeneous 
dathymetric data, provided by multiple providers, 
yarious sensors, various ages and survev qualitv. In