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 91 1098
AL 0 11888 158 628
AP 0 7 123 6
AR 0 7713 88 689
AS 0 0 4 15
AZ 0 20517 177 1947
CA 13 96174 504 9053
CO 28 18493 123 1419
CT 4 7362 47 319
DC 2 516 1 24
DE 0 1801 5 73
FL 54 43344 181 1822
GA 18 18595 180 963
GU 0 3 134 118
HI 0 2893 59 889
IA 10 6485 34 291
ID 10 9006 343 1113
IL 6 19670 275 750
IN 14 15529 224 556
KS 12 7183 39 379
KY 9 9169 391 523
LA 9 5930 85 369
MA 11 13335 17 810
MD 11 11177 41 424
ME 3 4208 14 550
MI 11 21115 338 731
MN 9 11534 44 423
MO 18 14381 804 782
MP 0 0 53 169
MS 6 4771 308 355
MT 3 3584 30 776
NC 30 21711 130 1398
ND 5 1473 40 131
NE 7 3695 21 188
NH 9 5338 41 527
NJ 11 13291 103 539
NM 4 5865 86 888
NV 5 7909 60 791
NY 29 26547 103 1649
OH 27 28005 133 826
OK 7 8552 1043 844
OR 25 18868 128 2233
PA 17 24322 152 880
PR 5 1502 2430 1319
RI 0 1954 1 92
SC 20 9920 138 478
SD 2 1958 28 142
TN 22 18962 308 924
TX 73 52428 442 3575
UT 16 17448 183 942
VA 26 20230 87 1159
VI 0 13 107 145
VT 0 1921 12 284
WA 30 31308 219 3538
WI 18 11324 82 393
WV 2 5465 178 738
WY 6 1815 19 403
Totals 657 730469 11189 53090