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 2267 87 1093
AL 0 11862 163 628
AP 0 7 125 6
AR 0 7671 90 692
AS 0 0 4 15
AZ 0 20442 176 1941
CA 0 96170 522 9088
CO 0 18458 128 1422
CT 0 7359 46 319
DC 0 516 1 25
DE 0 1792 5 72
FL 0 43330 181 1827
GA 0 18595 187 963
GU 0 3 137 120
HI 0 2896 65 892
IA 0 6487 33 285
ID 0 8959 340 1111
IL 0 19673 277 754
IN 0 15506 223 556
KS 0 7182 41 378
KY 0 9147 388 528
LA 0 5934 88 375
MA 0 13346 16 808
MD 0 11182 44 426
ME 0 4207 17 550
MI 0 21102 345 725
MN 0 11550 48 423
MO 0 14376 803 776
MP 0 0 56 175
MS 0 4768 311 352
MT 0 3571 28 773
NC 0 21691 134 1394
ND 0 1474 40 131
NE 0 3689 19 186
NH 0 5324 46 524
NJ 0 13294 107 544
NM 0 5858 86 895
NV 0 7878 60 796
NY 0 26550 104 1652
OH 0 27969 137 820
OK 0 8545 1036 842
OR 0 18870 130 2236
PA 0 24282 160 884
PR 0 1506 2394 1311
RI 0 1955 1 92
SC 0 9897 140 479
SD 0 1958 30 142
TN 0 18914 317 919
TX 57 52262 451 3568
UT 11 17452 187 940
VA 17 20204 81 1164
VI 0 13 108 146
VT 1 1911 12 285
WA 29 31242 220 3546
WI 26 11290 91 391
WV 7 5442 189 737
WY 5 1805 18 404
Totals 153 729633 11273 53126