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 2278 93 1051
AL 0 12061 152 612
AP 0 10 126 5
AR 0 7764 76 688
AS 0 0 4 15
AZ 0 20757 194 1939
CA 0 94790 415 8760
CO 0 18780 108 1416
CT 0 7354 39 320
DC 0 522 0 26
DE 0 1826 3 74
FL 0 44080 135 1804
GA 0 18846 137 959
GU 0 5 128 109
HI 0 2868 62 852
IA 0 6504 33 300
ID 0 9449 239 1142
IL 0 19643 286 732
IN 0 15652 235 555
KS 0 7246 39 379
KY 0 9349 384 511
LA 0 5979 93 363
MA 0 13370 19 808
MD 0 11180 45 415
ME 0 4246 10 547
MI 0 21196 368 745
MN 0 11604 59 431
MO 0 14437 847 772
MP 0 1 49 155
MS 0 4756 323 336
MT 0 3664 24 769
NC 0 22176 154 1366
ND 0 1464 49 126
NE 0 3737 19 184
NH 0 5408 23 527
NJ 0 13320 61 529
NM 0 5855 81 871
NV 0 8028 67 759
NY 0 26473 103 1610
OH 0 28110 121 817
OK 0 8668 1071 822
OR 0 19087 94 2226
PA 0 24631 125 898
PR 0 1578 2530 1316
RI 0 1945 1 87
SC 0 10129 120 478
SD 0 2034 31 145
TN 0 19673 49 935
TX 0 52977 364 3535
UT 0 17705 185 931
VA 0 20549 82 1162
VI 0 12 110 152
VT 0 1966 11 284
WA 0 31496 190 3504
WI 0 11428 76 405
WV 0 5537 134 724
WY 0 1897 15 416
Totals 0 736100 10591 52399