123 Coded Data Field: Latitude and Longitude (O;NR)
Field Definition and Scope
This field contains the geographic co-ordinates of the place described in the given record. It may occur only in records for place names.
In accordance with Unimarc Authorities, the format provides for referencing a rectangular shape, which , however is (currently) not supported in the CERL Thesaurus. A place is referenced by a single point.
Application of Content Designators
Indicators
both indicator positions are undefinded and therfore left blank
Subfields
$d Westernmost Longitude (NR)
The longitude of the western boundary of the rectangle circumscribing the described place
$e Easternmost Longitude (NR)
The longitude of the eastern boundary of the rectangle circumscribing the described place
$f Northernmost Latitude (NR)
The latitude of the northern boundary of the rectangle circumscribing the described place
$g Southernomst Latitude (NR)
The latitude of the southern boundary of the rectangle circumscribing the described place
Each subfield is fixed at 8 characters and contains the following data:
| Character Position | Definition | Content |
|---|---|---|
| 0 | A one-character code indicating the Hemisphere | w = west e = east n = north s = south |
| 1-3 | Degree | 3 numeric characters, right justified and zerofilled |
| 4-5 | Minute | 2 numeric characters, right justified and zerofilled |
| 6-7 | Second | 2 numeric characters, right justified and zerofilled |
Input Conventions
The co-ordinates for a place are given as a centre point. However, in compliance with the Unimarc Authorities format, a distinction between the westernmost and easternmost longitude and northernmost and southernmost latitude is made when a record is rendered in the CT Internal Format. For editing it is sufficient to fill in subfields $d (longitude) and $f (latitude). Once a record is saved, subfields $e and $g, repeating the values given in $d and $f are added automatically.
The order of subfields within this field doesn't matter. It might be most convenient to enter coordinates this way:
123 ##$fn0513202$de0095608.
Mapping
To create an RDF description, the following mapping is applied
| $d | wgs84_pos:long |
| $f | wgs84_pos:lat |
- wgs84_pos represents the namesapce “http://www.w3.org/2003/02/geo/wgs84_pos#”
- the numerical values of the co-ordinates are represented as decimal fractions
- the vocabulary used is Basic Geo (WGS84 lat/long) Vocabulary http://www.w3.org/2003/01/geo/
Mapping Example
<rdf:Description rdf:about="http://thesaurus.cerl.org/cnl00016172"> <wgs84_pos:lat>48.8700</wgs84_pos:lat> <wgs84_pos:long>2.3300</wgs84_pos:long> </rdf:Description>
Example
123 ##$de0095625$ee0095625$fn0513143$gn0513143
215 #1$aGöttingen$cDE$5GYMG
Internal Representation
{"data": {"location": {"point": { "long": "Longitude ($d)", "lat": "Latitude ($f)" }}}}
