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 2303 106 1022
AL 0 12057 164 612
AP 0 4 117 5
AR 0 7828 66 693
AS 0 0 4 15
AZ 0 20906 94 1928
CA 0 93541 386 8480
CO 0 18892 128 1401
CT 0 7346 20 316
DC 0 532 0 27
DE 0 1844 3 71
FL 0 43989 140 1782
GA 0 18905 156 932
GU 0 4 124 100
HI 0 2850 65 825
IA 0 6534 28 297
ID 0 9693 184 1139
IL 0 19633 256 723
IN 0 15828 74 555
KS 0 7246 43 367
KY 0 9746 100 499
LA 0 5974 109 356
MA 0 13306 21 801
MD 0 11176 40 401
ME 0 4224 12 540
MI 0 21130 404 751
MN 0 11578 68 439
MO 0 14397 878 758
MP 0 1 48 155
MS 0 4701 311 322
MT 0 3710 27 780
NC 0 22366 99 1365
ND 0 1452 47 124
NE 0 3753 19 184
NH 0 5458 25 532
NJ 0 13213 62 527
NM 0 5801 80 847
NV 0 8033 64 741
NY 0 26302 105 1586
OH 0 28109 109 816
OK 0 8613 1123 810
OR 0 19136 77 2180
PA 0 24616 121 898
PR 0 1687 2463 1304
RI 0 1943 2 86
SC 0 10255 123 479
SD 0 2059 38 138
TN 0 19964 61 933
TX 0 53090 372 3493
UT 0 17794 192 934
VA 0 20584 82 1153
VI 0 11 108 147
VT 0 1955 9 283
WA 0 31560 114 3466
WI 0 11519 44 398
WV 0 5566 126 708
WY 0 1939 14 420
Totals 0 736656 9855 51644