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 2266 115 1135
AL 0 11599 314 626
AP 0 2 120 7
AR 0 7531 150 702
AS 0 0 4 16
AZ 0 19914 383 1940
CA 0 96445 1060 9334
CO 0 18052 276 1402
CT 0 7352 62 318
DC 0 510 1 27
DE 0 1773 10 72
FL 0 42631 319 1842
GA 0 18047 643 966
GU 0 3 134 123
HI 0 2881 126 934
IA 0 6324 124 279
ID 0 8538 362 1113
IL 0 19561 358 752
IN 0 15212 366 553
KS 0 7072 95 384
KY 0 8934 478 526
LA 0 5907 132 384
MA 0 13217 44 811
MD 0 11128 71 427
ME 0 4126 41 546
MI 0 20752 492 728
MN 0 11473 102 410
MO 0 14084 930 782
MP 0 0 61 190
MS 0 4700 380 360
MT 0 3424 64 760
NC 0 21179 196 1388
ND 0 1438 50 134
NE 0 3606 98 181
NH 0 5222 62 519
NJ 0 13315 152 541
NM 0 5776 153 907
NV 0 7687 138 815
NY 0 26457 177 1654
OH 0 27626 377 818
OK 0 8311 1133 841
OR 0 18533 251 2271
PA 0 23723 452 874
PR 0 1143 2589 1271
RI 0 1943 7 93
SC 0 9587 255 488
SD 0 1869 48 141
TN 0 18329 438 912
TX 0 51215 943 3576
UT 0 17174 271 937
VA 0 20043 137 1189
VI 0 3 120 143
VT 0 1884 31 280
WA 0 30947 378 3515
WI 0 11080 184 405
WV 0 5205 386 769
WY 0 1713 49 398
Totals 0 718466 16892 53509