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macpacheco
January 21st 11, 06:16 AM
On Jan 21, 2:40*am, Sam Wormley > wrote:
> On 1/20/11 10:21 PM, Mxsmanic wrote:
>
> > Because it's important to eliminate all backups to GPS, otherwise things
> > become way more difficult for terrorists with their jamming and spoofing
> > equipment. The same reason the FAA dreams of shutting down all VORs.
>
> * *Background
> * * *http://en.wikipedia.org/wiki/LORAN#The_future_of_LORAN
>
> * *Federal Radio Navigation Plan
>
> http://www.navcen.uscg.gov/pdf/frp/frp2008/2008_Federal_Radionavigati...
>
> * *FAQ
> * * *http://www.gps.gov/support/faq/

My opinion is Loran-C was a crappy system (mainly due to poor
accuracy). As a primary means for navigation Loran-C was really a bad
idea. But eLoran, that's a completely different idea.
Shutdown down Loran-C operations (without destroying any
infrastructure needed for eLoran) wouldn't have been such a bad idea.
eLoran on the other hand would have been a very useful backup to GPS,
with it's 8 meter accuracy. Actually with 8 meter accuracy, eLoran
would be better than single frequency GPS. eLoran could have been used
to replace all DGPS stations, due to its long range and ability to
broadcast WAAS like corrections to GPS.
The FAA never said it plans to shutdown all VORs. Non essential VORs
will be decommissioned as they fail/require more than the normal
maintenance.
The really expensive part of the NAVAIDs ILS. At US$ 1 million a pop
to install and US$ 75k per yr to maintain, those are very expensive to
keep around.
Even than the plan is to also keep some ILSs as a last resort backup.
DMEs are actually far more important than VORs, since DME-DME is far
more accurate than VOR/DME or VOR/VOR navigation.
That's the plan in Europe, to eventually shutdown all VORs and keep a
minimum DME infra as a backup to GNSS + Egnos.
Upgrading current DME to active DME + GPS pseudolites would add a lot
of usefulness to current DME stations.
Wouldn't it be possible to add GPS like ranging to DGPS ? That could
be a solution now that Loran towers have been/will soon be dismantled.
The FUTURE of LORAN = none for USA. All hope ended with the
dismantling of Loran towers.
Do you think they will rebuild the transmission towers ?
UK however is moving forward with eLoran.

Alan Browne
January 21st 11, 03:01 PM
On 2011.01.21 1:16 , macpacheco wrote:
> On Jan 21, 2:40 am, Sam > wrote:
>> On 1/20/11 10:21 PM, Mxsmanic wrote:
>>
>>> Because it's important to eliminate all backups to GPS, otherwise things
>>> become way more difficult for terrorists with their jamming and spoofing
>>> equipment. The same reason the FAA dreams of shutting down all VORs.
>>
>> Background
>> http://en.wikipedia.org/wiki/LORAN#The_future_of_LORAN
>>
>> Federal Radio Navigation Plan
>>
>> http://www.navcen.uscg.gov/pdf/frp/frp2008/2008_Federal_Radionavigati...
>>
>> FAQ
>> http://www.gps.gov/support/faq/
>
> My opinion is Loran-C was a crappy system (mainly due to poor
> accuracy).

For its time, it was superbly accurate and highly repeatable. It's only
weak point was poor national coverage.

eLoran (and differential Omega for that matter) were desperate cries
from involved interests in dying segments.


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