Mapping the unmappable

(Like speaking the unspeakable.)

A tiny article for some future OpenStreetMap State of the Map Conference e.g., lightning talk. Alas -- I'm getting kind of old for this stuff. So maybe somebody else would like to use it. (原欲投稿發表, 但今已老了累了, 換別人改造、發表。)

by Dan Jacobson 積丹尼 (jidanni)

I discovered that I continually end up mapping things that companies and governments,

  1. don't want us to map, or at least

  2. cannot publicly provide the details of which, due to bureaucratic restraints.

But at the same time this info is right there clear to see. E.g.,

  1. Power line names and tower numbers, right there on signs clamped to towers.

  2. Military base operating unit name, right there printed on the bottom of No Parking signs outside the base. Example: Xinshe Zhongxingling.

  3. Cell tower base station company and number, confirmed with any simple cell signal app, when standing next to the tower.

(One could say this is an area where OpenStreetMap outshines the competition. E.g., Google Maps™ is not going to ruffle the feathers of governments or companies, plus such "slight details" are not seen as the main point of interest of their customer base, a driver searching for a hamburger, etc.)

OK, let's look at some cases.

  1. Power lines

    Luckily many power towers and lines are already on the map, thanks to people stringing them together from imagery and placing them on the map.

    Ah, so all that is missing is their names. Well, next time you have to pick a bus stop to switch buses at, or visit a convenience store, pick one that is near a tower. The tower will certainly have a name plate saying the e.g., "Nibblesford-Nurdston 012". This is our tower's tag:ref, and we also get to name the whole line, ref="Nibblesford-Nurdston". Yup, in just a couple of minutes we have gathered the information to name the entire multi-million dollar line!

    Hmmm, certain power companies have some Open Data available, but only on the location of their low-voltage poles. High-voltage is seen as part of vital national infrastructure etc. so that's why we end up needing to copy names off of signs.

  2. Military

    What is the name of the base?

    1. Ah right there on the bottom of the No Parking sign, or Notice of Road Construction, etc.: "By order of Third Signal Corps' (tag:operator), Nerblesome Base (tag:name) Command."

    2. Or hear a plan crash, and check the news the next day: "Special Forces Base Nurdsome Falls #123 Commander Nurrvowitz said at the news conference that he regretted the incident..."

    Don't expect a lot of Open Data from the military. It would take all the fun out of being military for them. Hence the need to copy names from signs, etc.

  3. Cell towers

    Cell towers, disguised or not, are vital communication infrastructure.

    Let's put them on the map. As e.g., knowing where they are will enable us to know if we should climb mountain A vs. mountain B, to get a clear line of sight to one, during an emergency.

    1. Tools

      1. Tags

        1. Tag:man_made=communications_tower#Mobile_phone

        2. Key:communication:mobile_phone

        3. Key:mimics, tower:construction=concealed

      2. Apps

        1. Many, e.g., Netmonitor.

    2. Method

      1. Notice odd looking water tower, odd looking palm tree, etc.

      2. Launch app. On the signal strength page if the dB numbers are not extreme then switch to the SIM card (you've got a pocket full of them, right?) of the right carrier.

      3. Walk in a circle around the suspected cell tower. The cell ID's antenna sector suffix should change once for each 120° etc. sector we pass through, and then finally back to the first when we reach 360°.

      4. OK, now we have all the information we need to use the above tags to place it on the map!

        Formats: e.g., 4G "106154015" corresponds to the human readable "414664-31". And after removing the sector suffix, and comparing that particular company(CHT)'s 3G cell IDs, "CHT 4664" would be a good Name for that cell tower. Additional details we have gleaned from the app could be used for Proposed_features/Telecommunications_tower.

    3. Discussion

      1. Yes, in some countries full public records are available. No need to personally seek out the towers.

      2. Don't expect companies to list them on their own. With all the people objecting to cell towers, don't even expect to find one shred of a name pasted to the door to figure out what company it belongs to. (What a mysterious building, whirring and chirping, with no phone number to contact in case of emergencies.)

      3. At least the companies' websites often have a (blurry) coverage map, from which the public can sort of guess what neighborhoods might have a cell tower.

      4. Q: What about OpenCellID etc. projects? A: those are mostly theoretical centers of cells, not physical tower locations.


  1. At least when we call the phone company we can say with confidence "Your cell tower #1234 is on fire, just in case you would like to know." Whereas before OpenStreetMap we would have to get into a long discussion about where the tower is located and if it is really theirs. So we have saved valuable minutes thus helped save property!

  2. At least the police can look up where power tower "Nibblesford-Nurdston 012" is without needing to wait until business hours to contact the electric company. Thus being able to rescue a lost hiker whose reported location is there. So we have helped save lives!

But wait! There are also

Things OpenStreetMap doesn't value enough

  1. Utility poles: Electric poles are barely rendered in the standard layer, and telephone poles currently not at all. Sure, in cities one just wishes they would all go away. Underground perhaps. But it rural areas being able to confirm we are standing next to pole "Niffsford 39" might make all the difference in being able to get to the campsite tonight.

  2. Electric meters: So what if it is meter #78-1234-67? Sure, in cities one could care less. What are you going to map next, bubble gum stuck to the street? Ah, but in rural areas being able to confirm that we have really reached meter #78-1234-67 might be the only clue for kilometers that we are really on the right track.

    Well what about GPS? Sure, but sometimes the GPS of the person who made the map, or is reading the map (us), hadn't fully warmed up. Or maybe they were using the ancient Nipplesburg Datum. Who knows?

Last modified: 2021-03-02 04:26:55 +0800