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 2272 94 1060
AL 0 12030 166 614
AP 0 10 126 4
AR 0 7759 76 688
AS 0 0 4 14
AZ 0 20720 206 1949
CA 0 95182 428 8809
CO 0 18766 109 1421
CT 0 7341 38 315
DC 0 521 1 25
DE 0 1826 3 76
FL 0 44030 133 1807
GA 0 18829 134 966
GU 0 5 130 112
HI 0 2871 63 857
IA 0 6511 30 299
ID 0 9420 238 1139
IL 0 19695 277 733
IN 0 15635 229 560
KS 0 7252 37 378
KY 0 9332 406 513
LA 0 5983 92 370
MA 0 13384 19 810
MD 0 11171 43 417
ME 0 4240 10 546
MI 0 21179 359 741
MN 0 11617 59 436
MO 0 14418 831 778
MP 0 1 50 159
MS 0 4762 318 339
MT 0 3645 23 767
NC 0 22152 143 1366
ND 0 1479 46 124
NE 0 3739 17 185
NH 0 5413 23 528
NJ 0 13343 62 529
NM 0 5872 82 876
NV 0 8007 62 763
NY 0 26491 99 1614
OH 0 28124 127 817
OK 0 8672 1065 824
OR 0 19039 92 2221
PA 0 24637 122 889
PR 0 1574 2466 1307
RI 0 1947 1 87
SC 0 10083 145 483
SD 0 2021 32 145
TN 0 19608 51 939
TX 0 52979 365 3527
UT 0 17653 177 931
VA 0 20507 78 1162
VI 0 12 111 151
VT 0 1969 11 287
WA 0 31488 186 3519
WI 0 11423 73 402
WV 0 5535 138 724
WY 0 1888 15 414
Totals 0 736062 10521 52516