# Presentation: 367981

## Registries, Dictionaries and URN’s 

## 	Overview

- Registries
- 	GML simple dictionaries
- 		Universal Resource Names
- 			Recommendations
- Will Will will his boat to his daughter?  (Galdos PPT)

- 2/12

**Notes:**
We have covered content and structure – now look at tools to manage definitions
Common practice of semantic use among grantees
Uniquely identify observation resources to support aggregation
Smartly manage our definitions, enumerations and patterns of use
Allow flexibility at provider facility

## 	Which Standard?

- 3/12

**Notes:**
Salinity may mean different things to different people
Registries and dictionaries are just a few of the tools out there to help negotiate the differences

Many alternatives, what standards are needed to manage definitions?
No real leader in managing discovery, metadata and other components of source definitions

## 	Repositories and Registries

_**	**__**Repositories and Registries**_

**Notes:**
Repository overview, the major pieces and purpose
Some of the terminology used
GEOSS has several sites running now
Work on separate pieces already exist
Many parts that make up the semantic control – and extended family
We can’t take on the whole picture – so ----

## 	Registry Alternatives

- CIR - DTL website	(dictionaries & schemas)
- http://csc.noaa.gov/ioos/schema

- 5/12

**Notes:**
Assessment of what's out there
Who really is responsible for which part?
Our approach via:
	prioritize on dictionaries and schemas
	simple web site for registry
	bare bones of what's needed for data modeling
	John will talk more on metadata

## 	Dictionaries – Purpose and Function

- Enumeration – hopefully stable and authoritative
**Formats**:  GML, *GML Simple Dictionary*, many custom, etc...

- 6/12

**Notes:**
Many choices
Can build you own
Example from the GML simple dictionary profile

## 	Dictionary Parts

**A** - URN

**B** - Vocabulary Term

**Notes:**
Quick dictionary overview to layout next couple of slides

## 	Universal Resource Names

- Classification system...
- Unique identification of a resource
- ...useful with multiple resources
- Resolving – not necessary
- Alternative to XLinks

- urn : org: branch : objectType : authority : version : code

- urn:ogc:def:crs:EPSG:6.6:4326

- 8/12

**Notes:**
When is a URN used?
Which parts are fixed
Branch: def, serviceType,specifications,dataFormat
ObjectTypes: CRS, Datum, Ellipsoid, Axis, Parameter, Method, UOM

## 	URN’s –Applied 

**USED IN A DICTIONARY**
- <name codeSpace="urn:x-noaa:def:verticalDatum:ioos:1.0:">MLLW</name>
**USED IN AN INSTANCE**
- <csc:verticalDatum codeSpace="urn:x-noaa:def:verticalDatum:ioos:1.0">MLLW</ioos:verticalDatum>

- urn:x-noaa:def:oceanographic:ioos:1.0:waterTemperature

- 9/12

**Notes:**
Experimental
Follow the OGC pattern
DEF only for now

## 	Vocabulary Selection

- lowerCamelCase

- SWE
- NWS
- CF-Names
- SWEET
- BODC
- Observation Registry
- NODC
- USGS
- EPA
- FGDC
- Many others...

- ISO Lexical Convention

- 10/12

- Vocabulary purpose
- Scope, detail/needs and community
- Administration – Robustness

## 	 Dictionaries

- conductivity
- currentDirection
- currentSpeed
- dissolvedOxygen
- fluorescence
- oceanColor
- salinity
- ...

- NWS NDFD

- 11/12

- 2 - Orthometric
- 7 - Tidal
- 19 - Ellipsoidal

- airPressure
- airTemperature
- dewPointTemperature
- relativeHumidity
- solarRadiation
- visibility
- precipitation
- windSpeed
- windDirection
- windGust

- 7 – SI Units
- 8 - Extended

- oceanographic

- meteorological

- units

- vertical datum

- NGS

## 	Update Process

- 10/12

- February 28 – individual comments on dictionaries and schemas
- Ongoing – peer reviewed requests for changes

## 	Recommendations

- Utilize the GML Simple Dictionary Profile
- Use the proposed dictionaries
- Use the proposed URN pattern
- Participate in the update process