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 2253 119 1150
AL 0 11586 303 638
AP 0 2 124 7
AR 0 7482 146 700
AS 0 0 4 17
AZ 0 19772 361 1948
CA 0 96641 1044 9402
CO 0 17902 268 1391
CT 0 7344 61 314
DC 0 506 1 28
DE 0 1764 9 70
FL 0 42351 310 1844
GA 0 18046 653 959
GU 0 3 136 122
HI 0 2903 128 941
IA 0 6282 121 274
ID 0 8446 343 1104
IL 0 19524 356 759
IN 0 15151 351 553
KS 0 7058 96 373
KY 0 8890 476 531
LA 0 5892 128 390
MA 0 13159 41 799
MD 0 11102 68 419
ME 0 4124 41 550
MI 0 20680 485 722
MN 0 11438 97 410
MO 0 14094 924 777
MP 0 1 57 184
MS 0 4711 372 362
MT 0 3375 60 749
NC 0 20978 182 1384
ND 0 1436 49 135
NE 0 3601 98 184
NH 0 5188 61 516
NJ 0 13283 140 534
NM 0 5758 150 905
NV 0 7626 137 823
NY 0 26413 175 1663
OH 0 27497 360 824
OK 0 8315 1104 830
OR 0 18403 243 2274
PA 0 23620 452 873
PR 0 1122 2520 1250
RI 0 1942 6 91
SC 0 9533 249 494
SD 0 1838 48 145
TN 0 18192 422 900
TX 0 50971 881 3559
UT 0 17033 264 934
VA 0 19914 138 1196
VI 0 3 122 146
VT 0 1865 30 281
WA 0 30846 366 3519
WI 0 11020 179 407
WV 0 5192 401 780
WY 0 1697 48 400
Totals 0 715768 16508 53534