2015 3/23 ELoran coming back?

patrick wentworth

patrick wentworth

Pre-takeoff checklist
Joined
May 18, 2010
Messages
265
Location
Santa Rosa, Ca
Display Name
Display name:
Patrick
I just got an e-mail about this being back on a docket...Anyone else get this ?..
Do we get to dumpster dive for our iiMorrow and north star units?




ILA international loran assn
All,

Right after you respond with your comment(s) to the Federal Register notice on eLoran, at:

https://www.federalregister.gov/art...capability-notice-request-for-public-comments

or, http://rntfnd.org/2015/03/22/us-announces-it-is-considering-eloran-wants-public-comment/


Then go to this link to see that Congress is in action also. Encourage your favorite representatives early and often!

http://garamendi.house.gov/press-release/garamendi-introduces-bipartisan-gps-backup-bill-safeguard-national-security-economy

Bob Lilley
Sec'y ILA
 
eLoran and Loran-C are two different animals, so don't expect your paperweights to suddenly become usable again. I was under the impression that the Loran-C system had been demolished, but now I learn that while no station is transmitting, about 50% of the towers are still standing (new transmitters and timers will be required, of course). Having commanded two Loran stations on remote islands, I was gratified to learn that eLoran will be unmanned.

Write your congressperson...the bill is HR 1678.

Bob Gardner
 
Last edited:
Well, there are people that enjoy restoring steam locomotive engines too, so.......
 
For those of us who have never even seen a LORAN receiver and grew up in the GPS era, why would I want the government to spend money this?
 
cowman said:
For those of us who have never even seen a LORAN receiver and grew up in the GPS era, why would I want the government to spend money this?
Click to expand...

For someone who had a King 8001 -01 Loran C unit back in 1985 and it was DAMN accurate.. I say.... Spend money on the program...IMHO...
 
N801BH said:
For someone who had a King 8001 -01 Loran C unit back in 1985 and it was DAMN accurate.. I say.... Spend money on the program...IMHO...
Click to expand...

Not doubting that it works, I'm just mostly wondering why I'd want to use that when I have GPS available.
 
cowman said:
Not doubting that it works, I'm just mostly wondering why I'd want to use that when I have GPS available.
Click to expand...

Just 1 EMF airburst will disable the entire GPS network.... Loran C would have kept on truckin with minor delays...
 
Yup, it's always good to have a backup!
 
cowman said:
For those of us who have never even seen a LORAN receiver and grew up in the GPS era, why would I want the government to spend money this?
Click to expand...

It is relatively easy to interfere with a GPS signal, because the signal is very low power. LORAN-C (and I assume e-LORAN) use much stronger signals that would be difficult to jam.

One big solar flare event could conceivable knock out a fair number of GPS satellites. The system, at least as currently built, isn't very robust.
 
Makes sense, depending on the cost involved. There's always VOR/NDB/DME or dead reckoning in case of emergency.

Would be nice if all the old boat anchor LORAN receivers everyone is yanking out would still be usable.
 
cowman said:
Not doubting that it works, I'm just mostly wondering why I'd want to use that when I have GPS available.
Click to expand...

GPS = satellite-based (duh)
Loran = terrestrial

GPS = very small wavelength, easily obstructed
Loran = very long wavelength, virtually impossible to obstruct

GPS received signal at the antenna = very weak
Loran received signal at the antenna = comparatively strong

Bottom line: eLoran is intended to be a backup to GPS, not a replacement. Before politics got into the act, the avionics industry was testing combination GPS/eLoran units.

It's no surprise that the US government is very short-sighted and has its sights set on the next election. Other nations around the world kept their Loran-C systems and are now converting to eLoran while we twiddle our fingers and write off the demise of Loran-C as just the cost of doing business.

Bob Gardner
 
Last edited:
cowman said:
Makes sense, depending on the cost involved. There's always VOR/NDB/DME or dead reckoning in case of emergency.

Would be nice if all the old boat anchor LORAN receivers everyone is yanking out would still be usable.
Click to expand...

Why would you want the Loran back for boats and not airplanes,GPS is now available in the marine environment.byou can always use the compass and time speed and distance for dead reckoning I the boat.
 
cowman said:
For those of us who have never even seen a LORAN receiver and grew up in the GPS era, why would I want the government to spend money this?
Click to expand...

Because the technology to completely jam an area hundreds of miles in diameter with sticks and stones technology depending on a GPS transmitter transmitting watts and make that jammed area move at will with stuff that would fit in a VW bug is trivial.

Jamming a megawatt loran operating at a frequency where antennas have to be hundreds of feet high to do any good at all is a mindboggling task and virtually impossible.

Jim
 
I've been hearing rumors about it for a while, but I think it's really going to be a completely different technology base, so like when Loran A went to Loran C none of the A equipment worked on it, similarly none of the old Loran C equipment will work on eLoran. This is all just what I have gathered from maritime industry gossip, not official sources.
 
The threat is not one of jamming that is the greatest concern. Commerce has become dependent on the fuel, time, and cost optimization these systems bring, and what the GPS system is most vulnerable to really is solar events. We can loose half the constellation or more in one major Coronal Mass Ejection. We can no longer operate to our current level of needs without these guidance systems, so a second system has been decided to be reinstated.
 
Henning said:
The threat is not one of jamming that is the greatest concern. Commerce has become dependent on the fuel, time, and cost optimization these systems bring, and what the GPS system is most vulnerable to really is solar events. We can loose half the constellation or more in one major Coronal Mass Ejection. We can no longer operate to our current level of needs without these guidance systems, so a second system has been decided to be reinstated.
Click to expand...

Cite please...
 
Old Geek said:
Cite please...
Click to expand...

Like I said before, various industry gossip and published articles in the trades, I have nothing definitive from an official source. Many cites were made of leaders of major shipping lines.
 
Between VORs and GPS I feel plenty safe.

If you guys want this stuff, what programs would you cut to free up the money required?

Remember this country is in a TON of debt, I'd rather see us stream line thing than print more money for programs and cheapen my dollar.
 
James331 said:
Between VORs and GPS I feel plenty safe.

If you guys want this stuff, what programs would you cut to free up the money required?

Remember this country is in a TON of debt, I'd rather see us stream line thing than print more money for programs and cheapen my dollar.
Click to expand...

VORs don't cover ships, air transport is a small fraction of the global logistics infrastructure that depends on electronic guidance. Even farm implements use precision electronic guidance now.

This is not just about aviation. What you want is completely irrelevant, business gets what they want and bills you for it. Business wants this.
 
Henning said:
VORs don't cover ships, air transport is a small fraction of the global logistics infrastructure that depends on electronic guidance. Even farm implements use precision electronic guidance now.

This is not just about aviation. What you want is completely irrelevant, business gets what they want and bills you for it. Business wants this.
Click to expand...

Tagging on to Henning, the technology is PNT: {Position, Navigation, Timing. GPS is used to synchronize our communications systems. Look at the base of any cell tower and you will see a little box with a GPS receiver in it....not for position but for timing.

As Henning notes, Loran-C and eLoran are different. I suggest that you spend a few moments with your friend Google, searching for eLoran.

Bob Gardner
 
weirdjim said:
Because the technology to completely jam an area hundreds of miles in diameter with sticks and stones technology depending on a GPS transmitter transmitting watts and make that jammed area move at will with stuff that would fit in a VW bug is trivial.

Jamming a megawatt loran operating at a frequency where antennas have to be hundreds of feet high to do any good at all is a mindboggling task and virtually impossible.

Jim
Click to expand...

Both of my stations had 625' towers....I climbed them both. A few, like Iwo Jima (or Marcus, I can't remember which) had a 1,300 foot tower. One of them collapsed during maintenance, killing four technicians.

Bob Gardner
 
bobmrg said:
Both of my stations had 625' towers....I climbed them both. A few, like Iwo Jima (or Marcus, I can't remember which) had a 1,300 foot tower. One of them collapsed during maintenance, killing four technicians.

Bob Gardner
Click to expand...

Holy crap, I would hate to have to maintain a metal antenna that big in the South Pacific climate. I can't imagine them lasting much more than 15 years, 25 tops.
 
bobmrg said:
GPS = satellite-based (duh)
Loran = terrestrial

GPS = very small wavelength, easily obstructed
Loran = very long wavelength, virtually impossible to obstruct

GPS received signal at the antenna = very weak
Loran received signal at the antenna = comparatively strong
Click to expand...

GPS - spread spectrum, relatively immune to noise and doesn't really need a "strong" signal.
LORAN - Low rate pulse modulation that works only with a strong enough signal and the absence of interference such as thunderstorms etc...so that there's an adequate SNR to do the timing comparisons


To correct an earlier statement. eLoran inserts a data modulation over the normal Loran-C so yes, the boat anchors might come back again provided you could otherwise configure them for the new system.
 
flyingron said:
GPS - spread spectrum, relatively immune to noise and doesn't really need a "strong" signal.
LORAN - Low rate pulse modulation that works only with a strong enough signal and the absence of interference such as thunderstorms etc...so that there's an adequate SNR to do the timing comparisons


To correct an earlier statement. eLoran inserts a data modulation over the normal Loran-C so yes, the boat anchors might come back again provided you could otherwise configure them for the new system.
Click to expand...

I think both systems can work hand in hand very well especially if the data stream can deliver weather.
 
Henning said:
Holy crap, I would hate to have to maintain a metal antenna that big in the South Pacific climate. I can't imagine them lasting much more than 15 years, 25 tops.
Click to expand...

It has been 50 years since I left Okinawa...don't know if that is one of the locations where the tower still exists and Google Earth doesn't help.

I don't know what kind of maintenance has been provided or who has been paying for it but I agree with you.

Bob Gardner
 
James331 said:
Between VORs and GPS I feel plenty safe.

If you guys want this stuff, what programs would you cut to free up the money required?

Remember this country is in a TON of debt, I'd rather see us stream line thing than print more money for programs and cheapen my dollar.
Click to expand...

There is a MASSIVE amount of waste in the guvmint.....

Just last week the story came out that Social Security was mailing out 6.5 MILLION checks each month to people who were listed as 111 years and older...

Facts show there are only 39 on this planet and 4 in the U.S.A....

The saving alone by not mailing out checks to 6.5 million crooks would free up 4.3 BILLION a year.....

That would cover GPS, LoranC, Loran E, and a few others navigation devices...
 
cowman said:
Not doubting that it works, I'm just mostly wondering why I'd want to use that when I have GPS available.
Click to expand...

How much does it cost to maintain GPS satelites versus land based transmiters?
 
Henning said:
I would think the system would dovetail into RNAV. I would think it would end up with VOR minimums at best.
Click to expand...

The side-by-side flight tests run by FreeFlight, the original Trimble folks, showed that the GPS track and the eLoran track coincided. I do not think that there is an argument that one is more accurate than the other.

Bob Gardner
 
Henning said:
Like I said before, various industry gossip and published articles in the trades, I have nothing definitive from an official source. Many cites were made of leaders of major shipping lines.
Click to expand...

Well, I read a GPS tech publication that comes out once a month and I've heard nothing like that. Certainly there's a possibility of intermittent service disruption, but I don't believe any sort of credible solar event would destroy the satellites.
 
bobmrg said:
The side-by-side flight tests run by FreeFlight, the original Trimble folks, showed that the GPS track and the eLoran track coincided. I do not think that there is an argument that one is more accurate than the other.

Bob Gardner
Click to expand...

But can you do vertical guidance from eLoran? I'm not sure how that would work.:dunno:
 
Old Geek said:
Well, I read a GPS tech publication that comes out once a month and I've heard nothing like that. Certainly there's a possibility of intermittent service disruption, but I don't believe any sort of credible solar event would destroy the satellites.
Click to expand...

A major coronal mass ejection can blow every transformer across the country. Satellites are not invulnerable either.
 
Henning said:
But can you do vertical guidance from eLoran? I'm not sure how that would work.:dunno:
Click to expand...

You're right..there is no WAAS equivalent with eLoran. But we are talking about the system's ability to recover from a major disruption and get everyone on the ground, not day-to-day eLoran operations for a protracted period.

Bob
 
Old Geek said:
Well, I read a GPS tech publication that comes out once a month and I've heard nothing like that. Certainly there's a possibility of intermittent service disruption, but I don't believe any sort of credible solar event would destroy the satellites.
Click to expand...

A fellow subscriber to GPS World? ;)
 
jonnyjetprop said:
Worldwide, governments are looking to backup technologies for GPS for all users, not just aviation.

http://www.gps.gov/governance/advisory/meetings/2014-06/lawrence.pdf

The FAA has stated that there will be a Minimal Operating Network (MON) of VOR stations until AFTER 2020. The FAA is looking at things like DME-DME and other forms of backup navigation.

http://www.faa.gov/air_traffic/flig...ns/12-02-Discon_of_VOR_Srvcs_presentation.pdf
Click to expand...

FTFY.

"Transitions from a legacy network of 967 VORs to a MON of
approximately 500 VORs by a target date of January 1, 2020"

Bob
 
You must log in or register to reply here.
Back
Top