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 2276 100 1032
AL 0 12039 157 613
AP 0 8 124 5
AR 0 7757 79 689
AS 0 0 3 15
AZ 0 20860 91 1932
CA 0 94536 423 8685
CO 0 18823 115 1409
CT 0 7344 37 319
DC 0 527 0 27
DE 0 1824 2 72
FL 0 44040 130 1795
GA 0 18873 139 949
GU 0 4 125 101
HI 0 2864 63 839
IA 0 6522 31 297
ID 0 9567 169 1143
IL 0 19585 296 732
IN 0 15660 246 553
KS 0 7237 40 376
KY 0 9656 102 507
LA 0 5973 104 361
MA 0 13360 19 807
MD 0 11165 45 405
ME 0 4231 8 545
MI 0 21204 382 746
MN 0 11584 64 430
MO 0 14456 847 769
MP 0 1 49 155
MS 0 4738 317 328
MT 0 3676 23 767
NC 0 22321 107 1375
ND 0 1467 52 122
NE 0 3753 18 185
NH 0 5417 24 525
NJ 0 13295 60 517
NM 0 5827 82 870
NV 0 8017 68 747
NY 0 26420 101 1606
OH 0 28063 120 813
OK 0 8653 1089 814
OR 0 19165 75 2211
PA 0 24621 126 898
PR 0 1599 2494 1305
RI 0 1946 1 85
SC 0 10188 120 476
SD 0 2029 33 144
TN 0 19768 52 940
TX 0 53020 359 3510
UT 0 17707 196 937
VA 0 20546 83 1165
VI 0 12 108 148
VT 0 1963 11 286
WA 0 31477 189 3492
WI 0 11444 78 407
WV 0 5550 133 721
WY 0 1912 14 422
Totals 0 736570 10123 52124