[Boatanchors] LightSquared (sort of)

[D C _Mac_ Macdonald]

LORAN (LOng RAnge Navigation) was developed to provide a 
locationing method over the oceans of the world.  It was 
positioned in the 1750 - 2000 kHz frequency spectrum. It 
was totally adequate to find England, France, or whatever 
from the USA. 
 
It did NOT work over land areas other than just a short 
distance inland from water.  I don't remember if LORAN 
was installed around the Great Lakes area. In February 
1962, fresh out of USAF Navigator school at Harlingen 
AFB, TX, I probably could have told you! 
 
As has been previously stated, it was deactivated in the USA 
around 1980. 
 
LORAN-C at VLF (Very Low Frequency) was developed long after 
LORAN-A, and was installed at some inland locations in the USA 
and did function fairly well.  Boaters, especially those engaged 
in fishing, really liked it because they could record coordinates 
(or TDs) of their favorite fishing spots down and find those 
spots again! 
 
The LORAN-C stations, maintained by the US Coast Guard, were 
deactivated a few (10 or so?) years back when the GPS constellation 
(group of satellites) was upgraded to WAAS (Wide Area Augmentation 
System) to enable a much higher level of accuracy than was previously 
available.  At one time, DGPS (Differential GPS) was available in 
some areas to provide a higher level of accuracy.  This used separate 
transmitters in the LF (Low Frequency) range (~200-500 kHz) at known 
ocations which transmitted short range (< 100 or so miles) corrections 
to be compared with those in the GPS receiver to gain that improved 
accuracy. These DGPS capabilities were usually in coastal areas that
had high concentrations of marine (civil and military) shipping. 

* * * * * * * * * * * 
* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* k2gkk at hotmail.com * 
* Oklahoma City, OK * 
* USAF & FAA (Ret.) * 
* * * * * * * * * * * 
 
 
 

 
 
 

> From: frledda at att.net
> To: jfor at quikus.com
> Date: Tue, 9 Oct 2012 08:50:30 -0500
> CC: boatanchors at mailman.qth.net; drewrailleur807 at yahoo.com
> Subject: Re: [Boatanchors] LightSquared
> 
> GPS by design can detect lack of accuracy; this can be done, since multiple
> solutions can be determined using different satellites; a cross check can
> identify errors. 
> 
> I don't know much about LORAN to know how it could compute multiple fixes to
> detect errors. Cross check with what? A GPS signal?
> 
> I know that LORAN is more than aviation, but I am familiar about aviation.
> 
> FL
> 
> -----Original Message-----
> From: J. Forster [mailto:jfor at quikus.com] 
> Sent: Tuesday, October 09, 2012 8:14 AM
> To: Francesco Ledda
> Cc: 'Drew P.'; boatanchors at mailman.qth.net
> Subject: RE: [Boatanchors] LightSquared
> 
> > The problem with LORAN was that there was no way to detect an error 
> > and/or degradation of accuracy; this limited its use for aviation 
> > application to enroute applications.
> 
> Well, since the potential shutdown was known for many years, no manufacturer
> was inclined to make the design effort to write the SW to provide cross
> checks. A chicken & egg problem.
> 
> Also, LORAN-C was never designed to be an ILS. It was certainly good enough
> to get you within a mile of your destination.
> 
> > LORAN had some problems when closing in to bad storms. I did 
> > experience the LORAN going "blank" at the "wrong time" due to heavy 
> > statics, few times; it is not fun, when flying.
> 
> Again, flying is NOT the one and only use.
> 
> > I still think that E-LORAN will come back one day.... may be, it is 
> > wishful thinking.
> >
> > FL
> 
> IMO, it will require a government that takes terrorism seriously or another
> 9/11 type incident.
> 
> "Ossama Bin Laden is dead,
> Al Queda is alive and well."
> 
> -John
> 
> =================