Loran C off the air

Mike O'Dell mo at ccr.org
Sun Aug 8 22:16:13 CDT 2010


everybody that looked at it said to keep Loran-C

The FAA said to, and a special panel which was created to
make the recommendation said to keep it. Note that ADS-B
is being deployed to maintain air traffic separation
while reducing radar coverage!

people don't understand just how many things are vulnerable,
not just because of "location" information, but because of
massive reliance on GPS for precision time distribution.
essentially all telecom timing is now disciplined and synchronized
using GPS signals. Loran-C signals were used before GPS became
readily available and it was still available as a backup.
obviously, no longer.

lose GPS and the communication networks will start falling apart,
some sooner than others. CDMA cellular systems need it, both
SONET synchronous and traditional plesiochronous timing will
start drifting. some will last longer than others but eventually
the clocks will start slipping and suddenly the wrong bits come out.

Sidebar: when people compare TDM networks with packet networks,
they talk about the reliability of TDM data delivery. actually,
the ONLY thing TDM promises is *when* to look for the next bit.
it makes no strong promise about it being correct, or even "your"
bit!  the error-checking is just laughable.

so when GPS gets blocked or jammed in a significant metro area
for a few hours, expect major grief.

On 8/8/10 9:37 PM, Tom Azlin N4ZPT wrote:
> I thought shutting down Loran was a debate that long proceeded Obama.
> But then I guess who ever is currently president gets blamed for
> everything that goes wrong and nothing that goes right.
>
> On 8/8/2010 8:33 PM, Chip Fetrow wrote:
>> I am on two other lists where this has been discussed to death.
>>
>> On the "broadcast list" there were a lot of comments about some Sun
>> effects taking out ALL of the GPS satellites.
>>
>> On another list, heavily populated by pilots, and some smart people, it
>> is the same.
>>
>> I think it is the second most bone-head play by Obama, and it saves VERY
>> LITTLE MONEY!
>>
>> We had already off-loaded the non US chains to other countries, who are
>> now paying to maintain them.
>>
>> The thing is, I used to use LORAN-A and LORAN-C in my car before GPS,
>> and actually after GPS was started because I was a GPS user when my
>> "hand held" unit was huge, only displayed Lat-Long, and the only
>> waypoint was MOB, for Man Over Board. OH, and it ate EIGHT C-Cells in
>> TWO HOURS!
>>
>> There were two major users, the airlines and ships at sea. Most
>> airliners removed them years ago, once GPS was approved for in-route
>> navigation, mostly for weight and panel space reasons. Of course,
>> LORAN-C was not nearly as useful, or useable on aircraft as LORAN-A,
>> with the former being Long-Wave requiring very long antennas, and
>> LORAN-A being Medium-Wave.
>>
>> I'm sure there are many on THIS list who know more than I.
>>
>> --chip
>>
>> On Aug 8, 2010, at 1:00 PM, tacos-request at amrad.org wrote:
>>
>>> Message: 2
>>> Date: Sat, 07 Aug 2010 18:15:21 -0400
>>> From: "Mike O'Dell" <mo at 131.ccr.org>
>>> Subject: Re: Loran C off the air
>>>
>>> i fear that the Stupid Tax payments arising from that
>>> incomrephensible decision are going to be staggering
>>>
>>> -mo
>>
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>
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