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 2269 88 1076
AL 0 11982 160 625
AP 0 10 119 4
AR 0 7748 81 692
AS 0 0 4 14
AZ 0 20628 190 1966
CA 0 95688 420 8906
CO 0 18684 121 1417
CT 0 7354 34 318
DC 0 520 1 24
DE 0 1806 3 75
FL 0 43857 127 1812
GA 0 18758 170 965
GU 0 4 129 114
HI 0 2871 65 863
IA 0 6515 29 300
ID 0 9380 225 1126
IL 0 19737 278 740
IN 0 15635 224 551
KS 0 7237 34 379
KY 0 9285 394 520
LA 0 6002 88 373
MA 0 13369 20 805
MD 0 11205 39 423
ME 0 4229 12 549
MI 0 21191 345 743
MN 0 11596 49 434
MO 0 14445 828 781
MP 0 1 50 161
MS 0 4777 316 345
MT 0 3638 23 768
NC 0 22050 129 1376
ND 0 1484 46 125
NE 0 3736 16 187
NH 0 5382 23 528
NJ 0 13332 94 534
NM 0 5889 81 880
NV 0 7979 59 779
NY 0 26604 97 1628
OH 0 28107 123 817
OK 0 8662 1049 833
OR 0 19080 89 2231
PA 0 24599 123 880
PR 0 1563 2431 1297
RI 0 1956 1 87
SC 0 10032 141 483
SD 0 2009 31 148
TN 0 19336 220 935
TX 0 52828 449 3535
UT 0 17645 172 942
VA 0 20449 95 1160
VI 0 13 108 149
VT 0 1973 10 285
WA 0 31471 186 3540
WI 0 11397 86 404
WV 0 5521 144 728
WY 0 1876 15 414
Totals 0 735394 10684 52774