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 2270 87 1083
AL 0 11976 160 626
AP 0 10 119 4
AR 0 7739 86 691
AS 0 0 3 14
AZ 0 20572 184 1963
CA 0 95835 473 8944
CO 0 18623 122 1415
CT 0 7383 34 317
DC 0 518 1 24
DE 0 1804 3 75
FL 0 43742 112 1812
GA 0 18724 167 965
GU 0 4 131 114
HI 0 2880 62 866
IA 0 6503 30 295
ID 0 9305 217 1116
IL 0 19721 283 745
IN 0 15609 223 553
KS 0 7235 35 377
KY 0 9267 381 519
LA 0 5998 84 369
MA 0 13371 20 796
MD 0 11226 39 419
ME 0 4222 12 554
MI 0 21143 341 743
MN 0 11570 48 430
MO 0 14442 820 785
MP 0 1 47 162
MS 0 4799 312 352
MT 0 3621 25 772
NC 0 21970 124 1381
ND 0 1484 41 129
NE 0 3729 16 185
NH 0 5362 24 530
NJ 0 13309 92 530
NM 0 5892 83 876
NV 0 7961 60 784
NY 0 26601 97 1630
OH 0 28084 121 825
OK 0 8635 1036 839
OR 0 19072 86 2237
PA 0 24506 127 873
PR 0 1552 2404 1304
RI 0 1947 1 90
SC 0 9996 136 479
SD 0 1995 29 146
TN 0 19155 316 933
TX 0 52708 434 3564
UT 0 17602 170 947
VA 0 20377 93 1158
VI 0 13 109 149
VT 0 1964 10 289
WA 0 31437 181 3544
WI 0 11375 85 401
WV 0 5509 157 738
WY 0 1845 15 409
Totals 0 734193 10708 52870