Permanent ID: Unterschied zwischen den Versionen
Aus Geoinformation HSR
Stefan (Diskussion | Beiträge) |
Stefan (Diskussion | Beiträge) K |
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| Zeile 5: | Zeile 5: | ||
The goal is to get an opaque fixed length ASCII string. And that are the design considerations: | The goal is to get an opaque fixed length ASCII string. And that are the design considerations: | ||
| − | * The OSM id alone is not stable enough (as probably most agree | + | * The OSM id alone is not stable enough (as probably most agree); and it can represent many concepts (and that's by design in OSM). |
* The version no. of the object is needed which makes clear which tags are (or have been) referred to. | * The version no. of the object is needed which makes clear which tags are (or have been) referred to. | ||
* Coordinates are needed, because a change of the geometry does not increment the version number. | * Coordinates are needed, because a change of the geometry does not increment the version number. | ||
| − | So a stable Permanent | + | So a stable Permanent ID could have the following form (which leads to a fixed length string of 35 chars in total): |
[N|W|R]<osm_id>#<version>[+|-]<lon>[+|-]<lat> | [N|W|R]<osm_id>#<version>[+|-]<lon>[+|-]<lat> | ||
where: | where: | ||
| + | * N,W,R stands for Node, Way, or Relation. | ||
* osm_id is left-padded with zeros to get 10 chars ("digits"), | * osm_id is left-padded with zeros to get 10 chars ("digits"), | ||
* version is 4 zero-padded digits | * version is 4 zero-padded digits | ||
| Zeile 20: | Zeile 21: | ||
Example: "Schloss Kyburg" (Castle Kyburg) has relation 1169711, | Example: "Schloss Kyburg" (Castle Kyburg) has relation 1169711, | ||
version #5 at coordinates 47.4584, 8.74343 which becomes following | version #5 at coordinates 47.4584, 8.74343 which becomes following | ||
| − | Permanent | + | Permanent ID: |
R0001169711#0005+47.45840+008.74343 | R0001169711#0005+47.45840+008.74343 | ||
Version vom 4. April 2019, 23:25 Uhr
This is an unofficial proposal for a "permanent ID" for OpenStreetMap (OSM).
See https://wiki.openstreetmap.org/wiki/Permanent_ID for a more official state of discussions.
The goal is to get an opaque fixed length ASCII string. And that are the design considerations:
- The OSM id alone is not stable enough (as probably most agree); and it can represent many concepts (and that's by design in OSM).
- The version no. of the object is needed which makes clear which tags are (or have been) referred to.
- Coordinates are needed, because a change of the geometry does not increment the version number.
So a stable Permanent ID could have the following form (which leads to a fixed length string of 35 chars in total):
[N|W|R]<osm_id>#<version>[+|-]<lon>[+|-]<lat>
where:
- N,W,R stands for Node, Way, or Relation.
- osm_id is left-padded with zeros to get 10 chars ("digits"),
- version is 4 zero-padded digits
- coordinates have 5 fixed decimal places (lat is 2 and lon is 3 decimal places, both signed and left-padded with zeros).
Example: "Schloss Kyburg" (Castle Kyburg) has relation 1169711, version #5 at coordinates 47.4584, 8.74343 which becomes following Permanent ID:
R0001169711#0005+47.45840+008.74343
