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 2284 95 1115
AL 0 11718 229 625
AP 0 6 126 7
AR 0 7609 99 703
AS 0 0 4 16
AZ 0 20217 155 1930
CA 0 96633 679 9287
CO 0 18253 139 1405
CT 0 7339 42 316
DC 0 510 1 27
DE 0 1783 4 73
FL 0 42971 177 1846
GA 0 18533 191 963
GU 0 3 134 121
HI 0 2907 93 921
IA 0 6409 44 279
ID 0 8664 322 1106
IL 0 19660 287 756
IN 0 15393 250 548
KS 0 7145 47 382
KY 0 9047 411 521
LA 0 5952 94 381
MA 0 13283 17 806
MD 0 11174 51 430
ME 0 4164 19 544
MI 0 20969 351 729
MN 0 11533 45 408
MO 0 14264 808 781
MP 0 0 62 190
MS 0 4745 333 357
MT 0 3499 32 756
NC 0 21387 137 1395
ND 0 1452 42 133
NE 0 3672 30 184
NH 0 5259 50 520
NJ 0 13309 111 539
NM 0 5826 97 904
NV 0 7793 64 816
NY 0 26535 132 1648
OH 0 27863 160 817
OK 0 8486 1003 837
OR 0 18723 129 2266
PA 0 24089 168 876
PR 0 1357 2393 1269
RI 0 1948 3 92
SC 0 9771 143 485
SD 0 1912 25 141
TN 0 18591 305 908
TX 0 51739 595 3577
UT 0 17322 195 943
VA 0 20130 83 1174
VI 0 6 117 145
VT 0 1898 19 278
WA 0 31151 223 3522
WI 0 11185 117 399
WV 0 5374 224 759
WY 0 1758 22 399
Totals 0 725203 11928 53355