The broadcast station location page is a search engine for AM,
FM, TV, and other broadcast stations. Searches for broadcast
stations by location, frequency, or call sign, and generates a
plain-text, tabular, or graphical map of the stations found. A
link to detailed information on each station is also provided.
The
Broadcast Station Location Page
is located at
http://www.jagunet.com/~kodis/station.html.
When you get there, you'll be able to specify several search
parameters. You'll have to provide either a
location or a
frequency range field
to limit the number of stations returned by a search;
the rest of the settings are all optional.
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The
Location
field will accept a city, a city and state, a zip code, or a
callsign to specify a location.
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The
Display
button lets you choose a map, table, or plain text display of the
stations found.
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The
other fields
are things that you might want to tweak, but the defaults are
generally okay. After hitting the submit button you'll have to
wait a few seconds for the search to complete. If you've asked
for a map, you'll have to wait another few seconds for that to be
prepared and transferred.
A location can be selected in any of several ways:
By Latitude and Longitude
This is the most fundamental type of location specification, and the
one into which the other methods must ultimately be resolved.
Any of several lat/lon formats can be used to specify a location. For
example, my home town could be specified as:
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n39:06:09, w76:27:37
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39o06'09"N / 76o27'37"W
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39.1025 -76.4603
as well as a few other variations. When in doubt, try it out.
Another format might work, and if not you'll just get an error
message.
By US City
Since people seldom know their latitude and longitude, but frequently
know what city and state they're in, a position can be specified,
albeit it roughly, by entering the city. If a city name isn't unique,
it can be followed by a state name or two-letter post office state
abbreviation. So if I specified my location as:
I'll get an error message listing the several different Pasadenas in
the gazetteer. To disambiguate these, I can enter either:
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Pasadena, Maryland
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pasadena, md
Note that capitalization is insignificant, that the state or province
must be separated from the city by a comma, and that either the full
state name or the two character state abbreviation can be used. Note
also that the gazetteer being used lists mainly large and mid-sized
towns and cities in the US, Canada, and Mexico, and that if a city
isn't contained in the gazetteer, its location cannot be determined.
Sorry, that's life.
By Zip Code
Although using a city to specify a location is convenient, it's also
generally quite imprecise, particularly when a major metropolitan area
is specified. A smaller region that people are also generally
familiar with is the area covered by their zip code. Although zip
codes aren't really meant to specify a geospatial coverage region,
they can be pressed into this service with a suitable zip code to
lat-lon database, as is done here.
So yet another way to supply the location of my home would be to enter
the zip code as either:
Note that only the five digit form of zip codes are available in the
database in use, so while the nine digit form will be cheerfully
accepted, the last four digits will be just as cheerfully ignored.
By Callsign
Finally, in some cases you might be interested in all the stations
near some other station. To allow for this, a station callsign can be
entered in the location field. A couple of good stations near me
include:
Note that here too case is insignificant, and that any AM, FM, or
TV suffix or any suffix beginning with a hyphen will be ignored in
performing the station search, and that if there's more than one
entry for a station, the location of the first station is used.
Note also that WRNR is just about the coolest callsign that a Rock
'n' Roll radio station could possibly have.
There are four display options available. The stations found can be
displayed as an HTML table, as plain text, as preformatted text, or as
a full color map of the locations of the stations found during the
search.
An HTML Table
This is the main form of display for the information retrieved from a
search. A one line summary is provided for each station found.
Included is the station's call sign, frequency or channel, antenna
information, power level, location, and the distance and bearing to
the transmitter.
The stations found are sorted first by frequency. If more than a
single station is found on a given frequency, the stations sharing the
frequency are then sorted by either distance, power, or antenna
height, as selected by the other options settings.
Each station's callsign provides a hyperlink to a display of detailed
information on that station. In addition to all of the information
included in the tabular station summary, this page provides several
additional items of information on the station such as the station's
owner, any comments entered for the station by the FCC, and a
graphical display of the radiation pattern for the station's antenna.
Plain Text or Preformatted Text
These text forms of display present the same information described for
the HTML table display above, but presented in a plain text format.
These are provided just in case anyone is still using a browser so old
that it doesn't support tables, or if the output is to be captured and
used for some other purpose. Normally, the HTML table display will be
preferred.
A Location Map
By selecting a map display, a very nice full color map of the
stations located in the search will be displayed. A location mark
will be provided by each station, with the callsign of the station
adjacent to its location mark. Unfortunately, the station
callsigns can really clutter up the map if a large number of
stations are selected for display.
By clicking on a location in the map, an HTML table of all the
stations found near that location will be generated. This gives
you a way to zoom in on the stations in an area of interest.
There are a few other things that can be adjusted when specifying a
search. Generally, the defaults provided are good choices, but you
may want to fine tune things here once you've done a search or two to
get the feel of things.
Limiting the Range of a Search
Searches are by default restricted to stations within 100 Km of a
location, which is roughly how far you can normally expect to receive
most types of broadcast stations. You can adjust this to suit your
reception conditions and level of optimism.
Changing the units of measure from the default units of kilometers to
statute or nautical miles effects not only the range but also the
units of measure used in the display of the distance to each station.
If a channel number or frequency is entered in this field, the search
will be restricted to stations broadcasting on this frequency. The
channel or frequency must be entered in the same format displayed in
the frequency column of the tables. This would be
- the frequency in KHz for AM stations, e.g., 540 or 1520;
- the frequency in MHz for FM stations, e.g., 88.9 or 103.1;
- the channel number for TV stations, e.g., 2 or 17.
A range of frequencies or channels can be specified by
entering two frequencies or channels as described above, separated
by a hyphen. Either end of this range can be omitted to restrict
the search to the upper or lower end of the band in question. This
allows searched to be restricted to
- FM stations on 93.5, along with neighboring adjacent and
alternate channel stations, by specifying 93.1-93.9;
- the VHF TV stations, by specifying -13;
- the AM stations in the new expanded portion of the band
above 1600 kHz, by specifying 1610-
Limiting the Number of Stations per Frequency
By default, only the two nearest stations on each frequency are
included in the search results. This can be altered by changing the
number entered in this field.
Changing the Station Sort Order
Normally stations on the same frequency are sorted by distance. This
can be changed to sort by power or antenna height. This effects which
stations are included in the search results display, and the order in
which the stations are listed in the station tabulations.
I'd like to be able to sort by expected signal strength at the
receiving site, where this is computed as a function of the distance,
effective radiated power, antenna height and radiation pattern, and
whatever else is applicable. I haven't gotten around to figuring out
how to do this yet, though. If anyone has a good algorithm for this,
please drop me a note. I'd be really pleased to add it to the
server code.
Finding all Stations on a Channel
If you're interested in generating a listing of all of the
stations on a specific frequency, enter your location as usual,
specify the frequency of interest, and crank the
Distance and Stations per Channel
fields up to the max. You might also want to change the
Sort Order from its default of Nearest
to Most Powerful.
None of this would have been possible without several databases and
supports sites. In the interest of providing credit where credit is
due, and in case anyone else is interested in making use of these same
resources, I've listed all of the bits and pieces here.
Broadcast Station Database Files
This series of database files is available through the courtesy of the
FCC.
Map Services
Courtesy of the Census Bureau's TMS server.
Gazetteers
Courtesy of the Census Bureau's TMS server.
Here are some other similar radio station location pages that you
might enjoy visiting as well.
If you know of any other services that you think should be added to
this list, please let me know about them.
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Broadcast Station Location Page
http://www.jagunet.com/~kodis/station.html
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A search engine for AM, FM, and TV broadcast stations based on the
FCC's engineering databases. Performs geospatial searches with a
wide assortment of sorting and search restriction options.
Displays tabular station summary data, detailed station
information, or maps showing locations of all stations meeting the
specified search criteria.
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Airwaves FCC Search Engine
http://www.airwaves.com/fccdb.html
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A search engine for the AM and FM broadcast bands based on the
FCC's engineering database. Features a tabular display of station
information, and a link to a map of each station's location.
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Welcome to www.radiostation.com From Elliott Broadcast Services
http://www.radiostation.com/
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And yet another search engine for the AM and FM broadcast bands
based on the FCC's engineering database. Offers a keyword search
capability. Features a detailed display of station information,
and a link to a map of each station's location.
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FCC Mass Media Bureau Audio Services Division FM Query
http://www.fcc.gov/mmb/asd/fmq.html
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The authoritative source -- ask the FCC themselves. Allows
queries for FM stations by callsign or file number.
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FCC FM Engineering Database Query
http://khavrinen.lcs.mit.edu/cgi-bin/query-fccdb
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This page permits you to inspect the contents of the FCC FM
Engineering database, using the station call letters as your
search string. You can also use the form st QQ, where QQ is a
two-letter state abbreviation, to list all stations in a state.
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Werner Funkenhauser's WHAMLOG Page
http://home.inforamp.net/~funk/
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WHAMLOG (c) 1995-1997 by Werner Funkenhauser, is a collection
of files of information extracted from a database of more than
21,000+ records that includes information about most AM radio
stations in the Western Hemisphere. The WHAMLOG series of
files reduces the data in the FCC's database to a size that is
more manageable by DXers because only relevant DX information
is extracted.
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The MIT List of Radio Stations on the Internet
http://wmbr.mit.edu/stations/
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This page lists all known sites on the Internet that publish
information about broadcast radio stations. It is unique in
that it also lists FM-cable and AM carrier-current stations.
I've put the source code for the station location page on my FTP site.
You can download a copy from my FTP site, which is located at
ftp://ftp.jagunet.com/pub/users/kodis/sloc.zip
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Convert the code to make use of the FCC's new style AM
database format.
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Handle locations like "Chicago IL", where there's only a space
between the city and state. Add some common, albeit non-standard,
state name abbreviations, such as "WVA", "N.Y.", "Calif", and so on.
Look for a gazetteer for non-us cities, especially for Canada
and Mexico.
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Shift frequency and other post-search filtering into the main
search loop, to avoid hitting the wall prematurly.
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Add snazzy waveform GIFs as background or headings.
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Add a search mode for FM and TV databases that includes
translators, transponders, and so on.
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Add search for National Weather Service weather stations, VLF
radiolocation beacons, DGPS stations, and any other class of
station for which I can obtain a station location database to
work from. Investigate the FCC SW station database as a
candidate for inclusion.
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Another interesting change would be to replace the AM-FM-TV
radio buttons with a set of check boxes, so that more than one
band could be selected simultaneously. Searching for the
resulting stations shouldn't be too hard, though displaying
the information in tabular form could be problematic because
of the differences in the information available for stations
in the various bands. Sorting the stations by frequency as is
done now would probably no longer be the best ordering for the
tables. This feature would, however, make for good looking map
displays.
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Find a way to predict field strength as a function of ERP,
HAAT, and distance. Use this to sort stations according to
expected signal strength. This could also be used to generate
some type of spectrum plot showing the relative strength of
co-channel, adjacent channel, alternate channel, and so on,
stations.
The Broadcast Station Location web page is brought to you by:
John Kodis, who will gladly receive comments, criticisms, or
suggestions sent to
kodis@jagunet.com
Last updated Saturday, 1997 May 31