Proposed features/Communications tower
The proposed tags are:
<tag k="man_made" v="communications_tower"/> <tag k="man_made" v="communications_transponder"/>
Communication towers which are used for broadcast or two-way communications via radio waves; such as radio, television, cellphones and two-way radio. Each tower may have 1 or 2 more transponders (antennas) attached to it, which is why this scheme abstracts out the transponders.
It is often possible to use these for visual orientation. In the case of cellphone towers, there are concerns about having these placed close to homes, so home-buyers might be interested in seeing their location on maps.
Some communication towers have further uses ( water tower, observation tower)
It is suggested that the Communication Tower node be rendered as follows:
The renderer may wish to use the height tag to gauge the size of the tower, to render the icon at different zoom factors or at different sizes.
It is suggested that the Communication Transponder node would not be rendered.
All communication towers using this tagging scheme should be tagged with man_made=tower
Some general tags which are used across many other types of object are used to tag communication towers:
|name||*||Name of the tower||Nose Hill Park|
|ref||*||Reference number of the tower||VE6RYC|
|operator||*||Maintainer/Operator of the tower structure.||Calgary Amateur Radio Association|
|height||*||Height of the top of the tower (including any antennas) from ground in meters. In the case where the tower is mounted on top of a building the height should include the height of the building.|
|ele||*||Elevation of the top of the tower (including any antennas) above sea-level in meters.|
|access||*||Physical access to tower, most likely private but some towers have viewing platforms.|
|source||*||Where did the data come from?||http://nwham.com/|
|website||*||Website with information about this Tower.||http://www.caraham.org/|
Tags which aren't shared with other OSM features are prefixed with the "communications_tower:" namespace.
|communications_tower:type||guyed_grounded||The whole or the upper part of the tower is anchored with guys to the ground. The tower is not electrically insolated against ground.||KVLY-TV Mast , Gerbrandy Tower , Behren-Bokel TV Mast |
|communications_tower:type||guyed_insulated||The whole or the upper part of the tower is anchored with guys to the ground. The tower is electrically insulated against ground ( most towers used for mediumwave broadcasting are in this category)||Mühlacker Radio Mast , Hirschlanden transmitter |
|communications_tower:type||freestanding_grounded||The tower is completely freestanding. No guys are used for its stabilization. The tower is not electrically insolated against ground||Stuttgart TV Tower , Croydon transmitter , Gliwice Radio Tower |
|communications_tower:type||freestanding_insulated||The tower is completely freestanding. No guys are used for its stabilization. The tower is electrically insulated against ground||Blosenbergturm , Junglinster Longwave Towers |
|communications_tower:type||dish||The 'tower' is a parabolic dish|
|communications_tower:type||dome||The 'tower' is a dome (or 'golf-ball') construction, with antenna elements concealed from view|
|communications_tower:type||concealed||The 'tower' is concealed/disguised (ie. made to look like a tree).|
|communications_tower:other||concealed||Communication towers which do not fit well in the above mentioned patterns||Russian Woodpecker |
|communications_tower:type||guy_anchor_basement||Basement of a guy|
A guy is a structure for keeping a tower or its upper part upright. Some wire antennas look also like guys, but are not used for keeping the tower upright. A tower only using such device is free-standing. The course of guys and antenna wires should be drawn-in.
Most communication towers will carry multiple transponders, each transponder must be characterised seperately and a relationship between the tower and the transponder made.
The 'communication_tower_group' relation shall contain the node representing the communication_tower and any/all communication_transponders.
In some cases a communication tower will only serve a single channel/frequency (ie. a single transponder), in which case the 'Communication_Transponder' tags may be applied directly the tower's node. It is unlikely that a single antenna would be mounted 1/2 up an (expensive) tower, so the height/ele tags should be consistent between tower and transponder.
There are also towers, which serve directly as antenna. Such structures are called mast radiators and are most common for frequencies below 10 MHz. Most of these towers are guyed and are insulated electrically against ground. However, there are also free-standing towers used for this purpose and some towers, which serve directly as antenna, are grounded.
It is also possible that a mast radiator carries antennas for transmission on higher frequencies.
Transponder General Tags
Some general tags which are used across many other types of object are used to tag communication_transponder:
|name||*||Name of the transponder||Nose Hill Park|
|ref||*||Callsign of the transponder||VE6RYC|
|operator||*||Maintainer/Operator of the transponder||Calgary Amateur Radio Association|
|height||*||Height of the transponder's antenna from ground in meters, at the tower location|
|ele||*||Elevation of transponder's antenna above sea-level in meters|
|source||*||Where did the data come from?||nwham.com|
|website||*||Website with information about this transponder.||http://www.caraham.org/|
Transponder Specific Tags
Tags which aren't shared with other OSM features are prefixed with the "communications_transponder:" namespace.
Transponder Technical Tags
These are included to suggest a scheme, but are not recommended for placing into the main OSM database.
Possible Sources of Geodata
- http://nwham.com/ - Amateur Radio Repeater Listing (permission granted to import)
- http://www.opencellid.org/ - Cell Tower Locations and transponder IDs (CC-SA 3.0 license)
- http://www.ic.gc.ca/eic/site/tafl-ltaf.nsf/eng/home Industry Canada - 'Frequency Assignment' data files.