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 2248 116 1168
AL 0 11426 270 625
AP 0 2 124 7
AR 0 7369 131 704
AS 0 0 4 17
AZ 0 19309 331 1918
CA 0 97138 960 9521
CO 0 17325 242 1334
CT 0 7353 52 318
DC 0 505 1 26
DE 0 1754 8 71
FL 0 41826 275 1863
GA 0 17765 596 964
GU 0 3 139 135
HI 0 2898 124 954
IA 0 6166 119 270
ID 0 7951 286 1062
IL 0 19376 348 741
IN 0 14982 323 537
KS 0 6999 89 367
KY 0 8737 441 530
LA 0 5858 120 394
MA 0 13125 37 791
MD 0 10922 62 411
ME 0 4072 42 550
MI 0 20429 447 712
MN 0 11301 91 401
MO 0 13935 859 766
MP 0 2 60 158
MS 0 4727 351 367
MT 0 3229 58 718
NC 0 20445 170 1365
ND 0 1422 46 134
NE 0 3591 101 183
NH 0 5106 48 500
NJ 0 13311 136 533
NM 0 5686 141 912
NV 0 7394 135 822
NY 0 26245 166 1651
OH 0 27312 341 810
OK 0 8204 1021 824
OR 0 18103 233 2267
PA 0 23379 442 855
PR 0 1112 2465 1254
RI 0 1930 6 83
SC 0 9347 216 494
SD 0 1787 43 138
TN 0 17611 360 890
TX 0 50322 771 3512
UT 0 16603 251 921
VA 0 19562 129 1172
VI 0 3 125 143
VT 0 1858 27 274
WA 0 30707 352 3485
WI 0 10902 152 399
WV 0 5142 426 818
WY 0 1655 49 390
Totals 0 707471 15458 53229