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 2251 95 1089
AL 0 11951 167 627
AP 0 9 120 5
AR 0 7729 88 689
AS 0 0 3 14
AZ 0 20531 183 1961
CA 0 95952 516 8977
CO 0 18592 129 1414
CT 0 7385 36 320
DC 0 521 1 24
DE 0 1803 4 75
FL 23 43638 187 1816
GA 22 18677 184 964
GU 1 4 130 114
HI 3 2879 61 874
IA 11 6477 34 287
ID 13 9117 349 1107
IL 55 19649 278 752
IN 26 15553 222 554
KS 5 7209 36 378
KY 12 9242 379 520
LA 10 5983 87 370
MA 17 13349 20 803
MD 8 11209 38 421
ME 8 4212 12 553
MI 17 21137 337 736
MN 9 11552 45 428
MO 13 14410 819 790
MP 0 1 49 162
MS 6 4784 308 351
MT 8 3595 30 779
NC 35 21855 136 1389
ND 2 1479 43 131
NE 4 3708 23 183
NH 3 5343 42 528
NJ 25 13257 97 534
NM 6 5869 85 880
NV 11 7925 60 786
NY 56 26534 101 1636
OH 34 28041 128 822
OK 12 8596 1035 840
OR 21 18946 128 2236
PA 33 24404 142 878
PR 8 1501 2447 1309
RI 2 1950 1 90
SC 20 9955 137 478
SD 5 1986 28 146
TN 39 19048 320 932
TX 81 52525 459 3566
UT 18 17504 177 950
VA 17 20326 91 1155
VI 1 13 109 149
VT 2 1956 13 290
WA 38 31338 220 3540
WI 13 11363 87 400
WV 4 5492 164 740
WY 0 1831 19 411
Totals 757 732146 11239 52953