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 2251 91 1094
AL 0 11922 160 627
AP 0 10 120 5
AR 0 7715 88 688
AS 0 0 3 14
AZ 0 20532 177 1955
CA 0 96056 519 9010
CO 0 18533 126 1425
CT 0 7366 47 321
DC 0 521 1 24
DE 0 1803 5 75
FL 0 43566 187 1825
GA 0 18642 183 966
GU 0 4 131 117
HI 0 2890 58 884
IA 0 6492 34 292
ID 0 9056 355 1104
IL 0 19671 279 753
IN 0 15539 226 560
KS 0 7196 38 380
KY 0 9184 395 519
LA 0 5945 89 369
MA 0 13368 19 812
MD 0 11204 43 424
ME 0 4217 15 555
MI 0 21117 343 730
MN 0 11560 44 424
MO 0 14411 819 784
MP 0 0 52 167
MS 0 4771 313 352
MT 0 3595 31 776
NC 0 21812 134 1392
ND 0 1480 41 131
NE 0 3704 21 187
NH 0 5340 45 528
NJ 0 13289 101 538
NM 0 5884 89 884
NV 0 7936 59 787
NY 0 26531 102 1641
OH 0 28060 137 826
OK 0 8562 1044 841
OR 0 18941 128 2234
PA 0 24384 156 877
PR 0 1509 2442 1316
RI 0 1956 1 93
SC 0 9918 142 484
SD 0 1973 27 143
TN 0 19026 321 933
TX 0 52590 453 3568
UT 0 17499 181 943
VA 0 20294 90 1159
VI 0 13 107 145
VT 0 1924 12 285
WA 0 31341 222 3546
WI 0 11347 89 392
WV 0 5480 177 743
WY 0 1826 19 408
Totals 0 731756 11331 53055