Minutes to the 7th North Sea Hydrographic Commission Resurvey Working Group

published at internal, NSHC, Resurvey Working Group | 4

HMS BELFAST, London, 7th– 8th November 2017



Mrs. Virginie Debuck (BEHO)

Mr. Bernd Vahrenkamp (BSH)

Mr. Jesper Vedel and Mr. Lars Hensen (DKHO)

Mr. Vincent Lamarre (SHOM)

Mr. John Loog (chairman) (minutes) (NLHO)

Mr. Thomas Warren-Locke (chairman) Mr. Phil Payne (Secretary) and Mr. Matthew Settle (UKHO)

Mr. Andrew Colenutt (observer) (MCA)



Mr. Ulf Olsson (SMA)


Welcome and Opening Formalities

  1. After a welcome from the chair quick and introductions discussions on the agenda commenced.
  2. Minutes for the 6th meeting with accepted without change.
  3. ToRs accepted without change.
  4. Agenda was adopted without change.
  5. Status of action items – see Annex A.


Update on NSHC and EU Developments

  1. Resurvey scheme overview and harmonisation. All agreed to present in the same way.  Three view (state of survey (CATZOC), resurvey plan, current planned surveys).  These would be put on a password protected section of the website.
  2. Risk Assessment. All DSSS states agreed to provide what they already have by 26th Jan 2018.
  3. DE asked about the status of the data model on the website. DE stated that EMODnet data was being used for countries that haven’t provided.  This was essentially a 50m grid.  The decision was made to keep on with link to EMODnet.  DK stated that they would only provide a 500m grid since switch to new Government Agency.

Updates on National Developments

  1. BE – An application for Wrecks and Belgian Continental Shelf surveys has been made based on their risk assessment. One new vessel for continental shelf survey has been procured with 3rd Party surveys continuing.  Bathymetric Lidar conducted by SHOM will take place in early 2018 based on new agreement that has been reached.  MBES ground truthing will be conducted to try and use lidar on charts.
  2. DE – Looking at newer higher resolution model out to 10m depth (1m grid). Use of more lidar data (topo and bathy).  Wind Farms increasing, so offshore work also increasing.
  3. DK – 2 new recommended routes based around a TSS off the northern tip. Survey effort for next 2 years to complete the survey of the 15 and 25m draught routes. (Looking at automated ships). General resource is 1 ship for 90 days a year.
  4. FR – 3 year plan. Some discrepancies between bathy database and charted CATZOC.  Dunes III underway to analyses the last 10 years of surveys.  Lidar surveys conducting with equipment rented from Leica and CAE Aviation (SHOM do all the work).  Offer made to UK to conduct lidar survey of Channel Islands during 2018 campaign.  EU Coastal Mapping Initiative to look at cross country lidar work (FR leading).
  5. NL – Plan and Policy remain the same with very minor tweeks. Possible change after SmartSea Project next year.
  6. UK – An update on recently completed and planned surveys for 2016-18 was given in terms of both capital and resurvey areas.


Requirement for a Common Exchange Format

  1. It was decided to use SHAPE files for exchange of areas. Those using ArcMap are also to provide. prj file.
  2. It was decided that S23 is to be used for limits of area. (N Sea, Skagerrak, Channel Islands, line Lands’ End to Brest)




  1. UK proposed that as an EU, not IHO project for which several MS are not a funding recipient it was inappropriate for EMODnet to be a standing agenda item for this group. It was agreed with the proviso that any items of specific interest to the work of the group should be raised by individual MS if raised by the EMODnet project.


Applicability of Alternative Survey Techniques


  • FR stated that https://shoals.sam.usace.army.mil/ is the only dedicated bathy lidar forum and worth attending.
  • UK continues to conduct lidar work outside of the North Sea area but will keep the group updated on any developments they see during the work.
  • NL use for recon only.
  • UK will provide paper on the use of SDB for charting.
  • FR are tendering for a study by end of year on empirical v full physical approach to SDB. 3 year programme. Tests have been conducted with hyperspectral imagery but they are not content with results. (CHS SDB Workshop 20-22 Feb 2018 in Ottawa)
  • DK – SDB test projects to be run in the far north of their areas.
  • DK – Are under pressure from Greenland Government to use CSB, but the general thinking is that this is not from a position of technical understanding. Use of ‘trusted CSB’ is being looked into for charting.
  • FR – Lots of opportunity are seen in the DSSS for change monitoring. SHOM see WG job to give advice on procedures.
  • DE – IHO Working group has published guidance but at 50 pages it is too long and too ‘hydrographic’. Open Sea Map project is of a much lower quality and the results are ‘terrible’ as not QC’d in any way.

It was noted that while originally CSB was for thought of as a tool for filling in white chart areas discussions held by the WG moved towards the use of it for change detection in areas of highly mobile seabed to better inform future resurvey work.

As a further note, across boundary data providers need to be coordinated with Trusted Partners to provide change analysis.  Action:  MS to comment on IHO CSB paper with regards to change analysis.

Autonomous Surveying
  • NL looking at AS with mine counter measures community. Remus was checked against MBES and found to be wanting.  Trial with Hugin v MBES due to take place which will be reported on at the next meeting.
  • DK – Currently use remotely operated 25m MCM boats.
  • FR – New ships to be fitted with UAV and USVs.


An area for the WG to keep an eye on, but are waiting on autonomous vehicle regulations from the IMO (sitting shortly).


Any Other Business


  1. NL are considering wave pattern monitoring to determine depths.
  2. DK are in the process of creating an LAT surface.
  3. UK are looking to provide a VORF update utilising the latest OSGM15 and latest tidal information.
  4. It was commented on that there are a number of specialist areas that come under the WG, and it would be useful for specific contacts to be made available. ACTION: send details for specific contacts to Bernd for inclusion on the restricted website.


Future Direction of the Working Group

  1. It was agreed that the 7th meeting contained a good mix of both formal and informal discussions on a wide range of issue pertinent to the main work of the group, and should be continued with a similar agenda in future years.


Closing Formalities

  1. France volunteered to host the next meeting in Paris in Sep/Oct 2018. Denmark volunteered to host the 2019.
  2. As the UK is currently chairing the WG it was agreed that the UK Rep may also act as Secretary if necessary.
  3. It was questioned whether Norway should be part of the WG. Action: Chair to confirm attendance of Norway at the WG.
  4. The chair thanked all members for their valuable contributions and the meeting was called to a close.




Annex A to

Minutes of the 7th NSHC RSWG

Status of Action Items from 6th Meeting



Action Item



1 Provide updated input to the overview of resurvey schemes

Resurvey plan


MS Overtaken by events.  See new actions 7-9.
2 Collect the information from MS and build the GIS-files and process combined overviews based on ArcGIS. The updated scheme will be handed over to all MS DE Overtaken by events.  See new action 2.
3 Provide the data for a publication of the overview on the internet. DE Overtaken by events.  See new action 2.
4 Each MS implements a link to the overview or publishes the overview on their website MS Ongoing.  See new action 3
8 Inform MS on progress of SmartSea Project NL Completed
9 Deliver Technical Hydrographic Instructions for the Dover Strait Survey Agreement, or a new version Fr, UK Carried over – see new action 1
14 Inform MS on MARID conference 4-6th April 2016 FR ToR amended to include reporting on conferences of interest. Completed
15 Create a password protected area within the NSHC website DE Discussed during meeting and agreed that the area needs to be able to upload files to exchange documents. Carried over –

See new action 2.

16 Report on the number of visitors on the NSHC website DE Completed post meeting. 7811 Unique visitors during 2017. Peak – Jul 17 – 17,000 per month.  Increase probably related to EMODnet use. Full analysis at Annex B.
17 Update the website with links to the INSPIRE portals of MS DE, assisted by MS Denmark will not provide link and not seen as a major issue.  MS to provide link if required – Complete


18 Provide input on “what depth value to use for gridding in which situation” MS Discussed during WG – Complete
19 Distribute paper “what depth value to use for gridding in which situation” UK due


20 Share link to paper “check on resurvey interval” with MS UK due


21 Share “report on SDB vs MBES” with MS UK due


23 Share “report on SDB vs MBES” with MS UK due


25 Change “DSSS termination letter” and send it to the parties NL Completed
26 Sign DSSS Agreement termination declaration BE, FR, NL, UK Completed
27 Provide data sets of S44 order, applied sensors and date of last survey from Dover Strait area BE, FR, NL, UK Overtaken by events. See Decision 4 and New Actions 7 – 9.
28 Create maps of the provided data sets DE Overtaken by events. See Decision 4 and New Actions 7 – 9.
29 provide examples of national projects on risk assessment and used data types BE, FR, NL, UK Overtaken by events. See Decision 4 and New Actions 7 – 9.
30 combine the input for the risk assessment question into a list FR Overtaken by events. See Decision 4 and New Action 10.
31 Discuss a national level what the outcome of the risk assessment for the Dover Strait area should look like. MS Overtaken by events. See Decision 4 and New Actions 10.



Annex B to

Minutes of the 7th NSHC RSWG

NSHC Re-survey Working Group – Decisions and Actions Lists


Number Decision item Responsible Comments
1 The creation of a common risk assessment or merging of individual risk assessments is not currently achievable.  Individual DSSS RAs to be provided as a discussion piece. BE, FR, NL, UK
2 SHAPE Files are to be used for the transfer of survey polygons. MS When supplying to DE a .prj file needs to be included.
3 EMODnet as an EU project will not be discussed as a separate agenda item during forthcoming meetings.  Individual MS are to report any developments of interest to the WG. Chair
4 All risk assessment and planning documentation to be made available on restricted area of website (see Action 2) until further discussions have taken place. DE
5 Applicability of alternate surveying methods to be kept as a standing agenda item. Chair To be included in TORs.
6 France to host 2018 WG
7 Denmark to host 2019 WG


Number Action item Responsible Comments Status
1 Deliver updates to the Technical Hydrographic Instructions,

(status of 31-12-2016 will be published on web site)

MS Awaiting FR 30 Nov 2017
2 Create a password protected area within the NSHC website DE due


3 Update the website with links to the INSPIRE portals of MS DE, assisted by MS ongoing
4 Share link to paper “check on resurvey interval” with MS UK due


5 Share “report on SDB vs MBES” with MS UK due


6 Publish THIs on web site DE due


7 Provide state of survey CATZOC polygons MS 26/01/2018
8 Provide planned survey areas for next season. MS 26/01/2018
9 Provide updates to resurvey frequency plan. MS As applicable 26/01/2018
10 Provide risk assessment outcomes (DSSS Area) BE, FR, NL, UK 26/01/2018
11 Comments on IHO CSB paper as relevant to seabed change analysis to be passed to chair. MS DE to publish draft IHO CSB WG paper on restricted website 26/01/2018
13 Provide DE with specific specialist contact details as required. (Eg lidar) MS To be published on restricted website area. 26/01/2018
14 Confirm attendance of Norway at WG. Chair



Annex C to

Minutes of the 7th NSHC RSWG

Statistics for Number of Visitors to NSHC Website

4 Responses

  1. Bernd
    | Reply

    The minutes are placed additionally on the homepage

  2. Phil Payne
    | Reply

    Bernd. No problem. Not sure if it would be possible, but perhaps using actual photos would be quite nice, especially when we have new members.

  3. Phil Payne
    | Reply

    Thanks Bernd for getting this site up and running. Hopefully it will become the backbone of our discussions and allow us to more easily share plans for onward discussions.

    • Bernd
      | Reply

      sorry Phil, your avatar image was generated automatically, I try to change it, if you want.

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