Amateur radio license map info

Welcome to my little spare time project. I've been working on this on and off for about a year as time and motivation allows.

This is more of an excuse to have some fun with Maps and Geocoding than anything else but it hopefully provides something interesting to play with. "Geocoding" means to convert physical addresses into longitude and latitude coordinates. Behind the scenes, this site has been slowly geocoding all active amateur radio addresses in the FCC license data. The FCC data includes all licenses which have a status of "active".

I've found it an interesting project with lots of little challenges. Some of this is because of the wide variation of population and therefore "ham density" throughout the country. I've had to balance that with performance issues both at the database query level and practical limitations of Google Maps. The data is also kind of messy with multiple licensees at one address and multiple addresses at the same location. This last issue is mostly due to spelling variations. In general, one marker appears on the map for each unique latitude / longitude point.

The performance / data quantity compromise I've come up with is that it searches within a 20 mile radius of the map center and has a limit of 200 location markers. The results are sorted by distance which means that the circle is complete until it hits the 200 markers. I haven't found a gridsquare that has more than 200 so if you center on a gridsquare, I think we always get all in that square.

The initial geocoding was done in bulk using Nominatim / OpenStreetMap. This succeeded in finding about half of all addresses. Then over a long period of time the rest were processed using Geocodio.

Geocoding continues using Geocodio at a rate of 125 per hour or a total of 2500 per day which keeps it within the free limit.  Every hour it selects 125 addresses from the database to geocode. These are chosen with the following priority.

  1. New addresses that have not be geocoded before.
  2. Those that previously succeeded on OpenStreetMap. Reprocessing these with Geocodio seems to be improving the results.
  3. Those that previously failed. Some now succeed because of better data.

A weekly import from the FCC usually happens early Wednesday morning eastern time. Only those stations with a status of "active" are retained. About 1000 addresses are added and deleted each week. Geocoding the new addresses is usually completed by late Wednesday.

Of course some addresses are PO Boxes and other mailing services. Addresses starting with "PO Box" are simply excluded. Also, many licensees are not active in the hobby. Be that as it may, it can be fun to play with the Street View feature of the maps to look for antennas.

Although I've only considered data from the USA, it's written in a generalized way so it can handle data from other countries but I'm not aware of any other countries who make their data publicly available.

It's built with Drupal 8. The code is all on Github here, here and here.

Anyway… I think it's pretty much "done" in terms of new features unless someone comes up with a good idea. I've probably spent way too much spare time on this already and it's time to get my antenna up again and do some QRP construction. Feedback is welcome. The easiest way is by email to tetranz (at) gmail.com

73
Ross  KT1F

Geocode report

StateNewSuccessfulNot FoundPO Box
AK 0 2262 88 1099
AL 0 11842 159 628
AP 0 6 122 7
AR 0 7671 90 695
AS 0 0 4 15
AZ 0 20392 159 1939
CA 0 96467 545 9182
CO 0 18458 125 1420
CT 0 7377 44 318
DC 0 516 1 24
DE 0 1797 4 72
FL 0 43203 174 1836
GA 0 18602 183 964
GU 0 3 137 121
HI 0 2892 75 901
IA 0 6495 33 281
ID 0 8899 334 1108
IL 0 19707 274 761
IN 0 15481 226 551
KS 0 7155 42 378
KY 0 9131 387 524
LA 0 5940 86 381
MA 0 13331 14 812
MD 0 11218 45 428
ME 0 4212 17 548
MI 0 21080 349 724
MN 0 11550 45 421
MO 0 14367 794 781
MP 0 0 58 180
MS 0 4776 310 355
MT 0 3558 24 765
NC 0 21600 125 1402
ND 0 1469 39 130
NE 0 3689 25 185
NH 0 5312 45 523
NJ 0 13327 107 540
NM 0 5865 87 902
NV 0 7848 56 803
NY 0 26583 102 1649
OH 0 27952 137 819
OK 0 8534 1016 839
OR 0 18844 121 2238
PA 0 24274 157 882
PR 0 1492 2326 1294
RI 0 1952 1 91
SC 0 9871 137 477
SD 0 1945 26 142
TN 0 18799 305 913
TX 0 52221 430 3568
UT 0 17454 185 935
VA 0 20223 80 1170
VI 0 13 108 144
VT 0 1914 12 286
WA 0 31260 218 3538
WI 0 11292 94 392
WV 0 5448 193 741
WY 0 1794 20 403
Totals 0 729363 11100 53225