Editing Low frequency (section)

===Radio navigation signals===
{{Expand section|date=June 2008}}
In parts of the world where there is no longwave broadcasting service, [[Non-directional beacon]]s used for aeronavigation operate on 190–300&nbsp;kHz (and beyond into the MW band). In Europe, Asia and Africa, the NDB allocation starts on 283.5&nbsp;kHz.

The [[LORAN]]-C radio navigation system operated on 100&nbsp;kHz.

In the past, the [[Decca Navigator System]] operated between 70&nbsp;kHz and 129&nbsp;kHz. The last Decca chains were closed down in 2000.

[[Differential GPS]] telemetry transmitters operate between 283.5 and 325&nbsp;kHz.<ref>
{{cite report
 |first = Alan (G4TMV) |last = Gale
 |year = 2011
 |title = World DGPS database for DXers
 |version = 4.6
 |url = http://www.ndblist.info/datamodes/worldDGPSfreqorder.pdf
 |access-date = 2008-01-14   |url-status = dead   |via = ndblist.info
 |archive-url = https://web.archive.org/web/20110721225343/http://www.ndblist.info/datamodes/worldDGPSfreqorder.pdf
 |archive-date = 2011-07-21
}}
</ref>

The commercial "[[Datatrak]]" radio navigation system operates on a number of frequencies, varying by country, between 120–148&nbsp;kHz.