1. Controlled Vocabularies and Coordinate Reference Systems

2. What is a vocabulary?
A person's vocabulary is the set of words within a language that are familiar to that person.
A vocabulary usually develops with age, and serves as a useful and fundamental tool for communication and acquiring knowledge.

3. Why use controlled vocabs?
Divided by a common language

4. Why use controlled vocabs?
Remove ambiguity
Support terms with explicit definitions
Publish on the web
Resource for all
Make explicit the implicit!

5. MEDIN & Controlled Vocabs
Where do MEDIN use controlled vocabs?
Data Guidelines and Discovery Metadata Standard
How to access the MEDIN vocabularies?

6. Example – Platform types
Populates the platformType field in Detailed Metadata in Data Guidelines

7. Availability through website

8. NVS2 Vocabulary client
Instruments, platforms, sea areas, geometries etc

9. MEDIN Keywords Keywords describe certain aspects of your dataset
MEDIN recommends “SeaDataNet Parameter Discovery Vocabulary” – P02

10. SeaDataNet hierarchies
Parameter relationships and discovery
How best to choose your P02 term? Can use

11. NVS2 Vocab Service: Hosted at BODC. Manual search link is:
Uses Simple Knowledge Organization System (SKOS) concepts to build URLs:
Format is:
Example:
Fully computer readable. Output in XML

12. Other Useful Vocabularies

13. How to add? E-mail Sean Gaffney sgaf@bodc.ac.uk
- check with appropriate governance group.

14. Knowing where a measurement or observation occurs is critical!
Coordinate Reference
Systems
Knowing where a measurement or observation occurs is critical!
Are the following numbers enough to provide precise positions of sampled data?
The data were sampled at ,
The data came from an area 6 miles from the lighthouse, bearing 245 degrees
The data are from 54 degrees 10’ 45’’ North, 3 degrees 30’ 20’’ West

15. Coordinate Reference
Systems
Coordinates define a position unambiguously only when the reference system that those coordinates are part of has been identified! LATITUDE and LONGITUDE are NOT UNIQUE!

16. Coordinate Reference
Systems
What is a CRS?
This is a coordinate system which is referenced to the earth based on a datum.
OGP, 2007, Surveying and Positioning Guidance note 1

17. Where is the Eiffel Tower? Coordinates: 48°51’29’’N, 2°17’40’’E
Coordinate Reference
Systems
Where is the Eiffel Tower?
Coordinates:
48°51’29’’N, 2°17’40’’E
OGP, 2007, Surveying and Positioning Guidance note 1

18. Coordinate Reference
Systems – implications!
Platform drilling . Meridional grid wrongly applied in directional software. 12 dry wells dug. Loss of capital expenditure of $2 million. Reputation damage. New program of work needed
Construction. Proposed position for new subsea manifold issued on ED50 datum. Contractor assumed positions in WGS-84 and drilled in wrong place. Resulted in fine of $500,000, reputational damage and contract dispute between contract parties

19. Practical
Aim – to familiarise yourself with different controlled vocabularies
Navigate to the MEDIN webpage for controlled vocabularies
2) Find:
Two different area codes for the Irish Sea (use SeaDataNet vocabularies)
The AphiaID for UK species ‘Mytilus edulis’ (use MSBIAS)
Code for the horizontal coordinate reference system WGS 84 [2D geographic, world] (use EPSG)
The code, vocabulary name and associated date for a Keyword for “Man-made Structure”
WIN AN AMAZING PRIZE 

20. Answers a)1_4 (using SeaVoX gazeteer)
[or 19 using SeaDataNet sea areas] *
b)140480
c) EPSG: 4326
d) MMST
SeaDataNet Parameter Discovery Vocabulary
date last modified
* - SeaVoX, not SeaDataNet sea areas, is the agreed MEDIN vocabulary for water bodies