Anyone heard about turning LORAN back on in CONUS?

I am intrigued by the part about establishing a worldwide 100 kHz timing signal first using existing government owned radio spectrum, and being able to sell it as a backup source for GPS timing. That could bring in billions of dollars. Would it be profitable? Of course, linking that word and government has a rather poor track record.

The average person has no idea how dependent our society is on the GPS timing signal. It is intertwined with literally everything around us, allowing events timed in nanoseconds to operate in concert.

If it were to fail one day, there would be unbelievable chaos in just about every system and industry. I can't even begin to list the specifics. A data center literally cannot operate without it. Cloud computing systems worldwide would collapse.

Global manufacturing would stop. Stock markets and banking sectors in every country would be unable to function, and every computing system connected to the internet would be affected. In fact, the internet would just quit working.

Before I retired, I was a principal in a general and electrical contracting business which built large data centers. The GPS antenna location, the routes and methods used to bring that signal into the rack space, and the protection and security of the system were extremely critical in even the smallest facilities.

Since I no longer deal with this issue, I wonder to what extent the Russian GLONASS system is being used as a backup timing system in today's world. Would someone in the industry care to share their perspective?

I ask because my cynical side is considering the cost of implementing a new system paid for with deficit spending while GLONASS could be integrated tomorrow.

As for general aviation, if a modernized LORAN system appeared tomorrow, making it work in your airplane would be similar to what the adoption of ADS-B has necessitated. In other words, you would have to shell out an uncomfortably large sum of cash. :confused:
 
3393RP said:
As for general aviation, if a modernized LORAN system appeared tomorrow, making it work in your airplane would be similar to what the adoption of ADS-B has necessitated. In other words, you would have to shell out an uncomfortably large sum of cash. :confused:
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For a panel mount solution, I’m sure it would be very pricey. However, I’m sure companies would develop iPad solutions similar to the existing external GPS units at a reasonable price. After all, it is just a backup solution so little need to go panel mount.
 
Pretty sure the loran towers have been taken down. This was some high power low frequency hardware, not the kind of equipment you could buy off the shelf.
 
eLORAN is not the same as the old system so this will not revitalize old gear. They destroyed the transmitter towers and stations when they decommissioned LORAN.
 
3393RP said:
The average person has no idea how dependent our society is on the GPS timing signal. It is intertwined with literally everything around us, allowing events timed in nanoseconds to operate in concert.

If it were to fail one day, there would be unbelievable chaos in just about every system and industry. I can't even begin to list the specifics. A data center literally cannot operate without it. Cloud computing systems worldwide would collapse.
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I'd be far more concerned about its effects on navigation. What you describe is a bit ... hyperbolic.

Be careful not to repeat the (il)logic behind the silly Y2K scare back in 1999. Those of us who rely on GPS (we do so, for both timing and frequency control) have disciplined oscillators and clocks that can maintain the correct time/frequency for many days in the event of a loss of GPS. Anyone who sets up one of these systems to solely use GPS *directly* is asking for trouble, so we don't do it that way.

(During the Y2K madness, whenever someone would say, "if this system goes down, chaos would result!" I'd always ask, "OK, so what do they do if it fails NOW?")

First, the loss of the entire GPS constellation is extremely unlikely. My time would be more profitably spent watching for asteroids. Second, even if it did occur, it would be bad, some services would scramble, but the idea of world-wide meltdown is ... a stretch.

The Internet would survive. Maybe some slowdowns or "try again later," but just as with Y2K, your assumption is that those of us who maintain these systems would go, "oh, no ... wuuuhhh ... what do we DO?" We KNOW what to do, because we have failures NOW.
 
My observations have no relationship to Y2K, and I don't think they are hyperbolic. More like fantasy.

First of all, I absolutely agree with your statement that the probability of a widespread failure of the GPS system is infinitesimal. The six satellites a cheapo handheld receiver sees are all independent from each other in most respects. What could make them all quit at once?

My daydreaming of something which cripples the entire system supposing some sort of global off command is silly. It'll never happen.

But, if it did, and didn't come back on, what I described would eventually come to pass in some form. Those trillions of data packets need help in being reassembled. The degree isn't worth arguing about, I was just letting the marbles in my head roll around.

I should have said something like "Does everyone know how much stuff in our lives requires synchronicity to work correctly?" and stopped there, but I've been up all night with a bad cold and therefore posted some good old internet nonsense. :confused:
 
IK04 said:
There was a bill to reauthorize a backup to GPS:

https://www.congress.gov/bill/115th-congress/senate-bill/2220/text

The eLORAN system is being started up in other parts of the Globe and Korea has developed their own system.

I had a King marine LORAN system that was accurate to a few feet. I sure would like to be able to use it again...
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Do you need a boat anchor or paperweight? If and when eLoran comes to life you will need a new receiver because it transmits on a wholly different frequency and does not rely on wave-form matching.

Bob Gardner
One-time skipper of two Loran stations
 
I actually had a random conversation with someone a few months ago who said their nephew was making good money traveling all over the world setting up new "LORAN" stations (I presumed at the time that they meant eLORAN). I thought that was pretty interesting. Gave me hope something like that might make it's way here again. There has been so much GPS jamming lately I decided to install a DME back in to my plane during my major panel upgrade just to have some backup, I'd be happy to see eLORAN as an option.
 
bobmrg said:
Do you need a boat anchor or paperweight? If and when eLoran comes to life you will need a new receiver because it transmits on a wholly different frequency and does not rely on wave-form matching.

Bob Gardner
One-time skipper of two Loran stations
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Yeah, that part was a joke :rolleyes:

I'm glad to know you were intimately familiar with the system. I always thought it was a bad idea to shut down the US based stations. It's been a while since I checked, but as far as I know, there are still active stations elsewhere on the globe.

When I lived in Savannah, GA, I had the unit in my car with a custom antenna and I used it to get accurate speed and distance info. I set the anchor watch to my parking spot in front of my townhouse and it was dead accurate to within a couple of feet!

I was in Korea last year and I saw one of their stations. The towers are massive and not like anything I've seen in the LF/SLF spectrum.

In a former life, I flew an airplane that had a blended VLF/Omega/LORAN-C nav package. It was true RNAV with VOR as a secondary... Cool!
 
Did/does loran provide altitude information?
 
Salty said:
Did/does loran provide altitude information?
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Reaching far back into the memory banks in my head, the two planes with loran units I flew back in the olden days did not display altitude information.

But as I said, those memories are quickly fading.....
 
3393RP said:
If it were to fail one day, there would be unbelievable chaos in just about every system and industry.
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How many Apocalyptic statements have we seen here before?
What is exactly "fail one day", all GPS satellites would disappear or stop functioning?
Minimum 3 are required for crude position estimate, I was flying yesterday and my aircraft could receive over 10 satellites.
And why GLONASS, there is also European Galileo.
Russian Ministry of Transport came up with an initiative that by certain date all Russian airlines should use GLONASS, purely politically motivated decision that as most predict - will amount to nothing, nada, zero.
The bulk of their fleet is western made with no support for GLONASS, one can imagine now Russian airlines paying manufacturers of FMS's equipment huge $$ to develop and certify a special version FMS just for them.

Were GPS to "fail" tomorrow - we would probably be facing such Armageddon anyway, such cataclysm that few would care about internet, stock market, etc - it would be survival of the fittest.
 
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3393RP said:
My daydreaming of something which cripples the entire system supposing some sort of global off command is silly. It'll never happen.

But, if it did, and didn't come back on, what I described would eventually come to pass in some form. Those trillions of data packets need help in being reassembled. The degree isn't worth arguing about, I was just letting the marbles in my head roll around.

I should have said something like "Does everyone know how much stuff in our lives requires synchronicity to work correctly?" and stopped there, but I've been up all night with a bad cold and therefore posted some good old internet nonsense. :confused:
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The general answer to the question highlighted in red above is... "Not a whole lot, really". Reassembling network packets doesn't rely on precise timing... period. The protocols include counters needed to reassemble packets received out of order, even if substantially ("substantially" in network terms, anyway) delayed or out of order.

Network equipment ran for decades with NO local clock setting; in fact, much still does to this day. It's amazing how many systems are running with no time sync at all; the local clock gets restarted every time the box powers up or reboots, and never does get set. Millions and millions more routers, switches, appliances, and servers are simply using Internet based NTP services, not GPS receivers. Yes, the NTP servers are generally using GPS timing -- but many have other time sources, such as WWV/WWVB and other time broadcast services. The concept of a widespread, persistent GPS outage has actually occurred to most people in the engineering space. We don't consider it an apocalyptic event, we think of it as a statistical near certainty. A lot of the obsession with time sync in large corporate datacenter environments has more to do with logging and event correlation for security and monitoring, really.

There are a few businesses that do rely on millisecond or sub-millisecond time synchronization between systems. I am personally most familiar with some banking and brokerage systems. Even those won't stop functioning or run off the rails if the time isn't synced; the companies may just not make quite as much money on trades. And even that is debatable, as long as all of their systems are in agreement on the time. That part is easily accomplished, whether the master time source is actually perfectly in sync with "real time" or not. Lots and lots of engineering goes into increasing and preserving profits. :)
 
I see the future in multi-constellation receivers with support for GPS, GLONASS, and maybe Galileo, too. Highly unlikely that all three systems could be taken out together, and they actually provide benefits at all times (e.g. more visible satellites for better geometry and position accuracy) as opposed to only being a backup.
 
I have done a bit of reading on the benefits of loran. It seems Loran is highly resistant to jamming, unlike GPS which is easily jammed. The newer Loran technology is nearly as accurate as GPS (non-waas) and because only a few Loran transmitters are required for worldwide navigation, maintaining and securing the Loran system may be a cost effective backup to GPS.
 
TigerGene said:
I have done a bit of reading on the benefits of loran. It seems Loran is highly resistant to jamming, unlike GPS which is easily jammed. The newer Loran technology is nearly as accurate as GPS (non-waas) and because only a few Loran transmitters are required for worldwide navigation, maintaining and securing the Loran system may be a cost effective backup to GPS.
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I can't speak to anything technical about the signal, but I think the main reason they were/are "resistant" to jamming is they are very high powered signals, so to effectively drown them out, is much more involved than GPS. GPS is an extremely weak signal by the time it reaches here, so a trucker with a few mW GPS jammer bought off Alibaba from China so his employer can't see his unscheduled stops can wreak reasonably widespread havoc.
 
@DaleB is correct. Network transactions have a time stamp but it is relative to the computer in which it is being processed. Applications, on the other hand, may have tight time tolerances - especially in the trading world. I work in the healthcare industry and our apps very much want time sync for many reasons but not to the second and none of the systems rely on GPS for time.
 
In addition to GPS and Glonass there is the European Galileo which is I believe operational and the Chinese BeiDou.

https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)
This seems to use newer technology than that used by GPS with improved accuracy. 1 metre resolution free and 1cm if you pay.

"All major GNSS receiver chips support Galileo and hundreds of end-user devices are compatible with Galileo.[4][119][120] Since 2017, the first mainstream smartphones with this capability were Samsung Galaxy S8, Moto X4,[121][122] Apple iPhone 8 and Apple iPhone X"

https://en.wikipedia.org/wiki/BeiDou_Navigation_Satellite_System#BeiDou-2
The global navigation system should be finished by 2020.[68] ... as of December 2017, 150m Chinese smartphones (20% of the market) were equipped to utilize Beidou.[69]
 
LORAN was great technology and it utilizes very different frequencies and powers compared to global satellite positioning technologies. eLORAN has the same horizontal spatial resolution of non WAAS GPS, enabling non precision approaches. It just doesn't have geometry or accuracy to provide good vertical guidance. A plus is it doesn't need line of sight. A minus is it is potentially susceptible to static discharge interference. Compared to the VOR system it is relatively inexpensive to maintain. GPS is great until the military practices jamming it for a week in your locale.
 
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The backup that I’ve been told about will be the MON VOR network above 5000’ and MLAT sites for a “faux radar return” on their consoles.

MLAT sites are already being used for ground resolution radar feeds in the rugged areas of the Rocky Mountains and Smokey’s.

So the MON network will get you to a ILS and ATC will be able to see you via MLAT.
 
I've walked two retired LORAN facilities, (Searchlight, NV and Las Cruces, NM). I can tell you there's nothing left there, as far as towers, equipment, or copper wire for that matter. Just old buildings, and in general, lots and lots of shotgun shells and bullet casings on the ground, literally everywhere.
 
Stephen Poole said:
The Internet would survive. Maybe some slowdowns or "try again later,"
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I'm still trying to figure out why a GPS loss would cause the internet to "just quit working". In all the routers I've setup, not a single one needed a GPS clock to sent/receive routing updates or forward packets. :D

hyperbolic indeed.
 
3393RP said:
My observations have no relationship to Y2K, and I don't think they are hyperbolic. More like fantasy.

First of all, I absolutely agree with your statement that the probability of a widespread failure of the GPS system is infinitesimal. The six satellites a cheapo handheld receiver sees are all independent from each other in most respects. What could make them all quit at once?

My daydreaming of something which cripples the entire system supposing some sort of global off command is silly. It'll never happen.

But, if it did, and didn't come back on, what I described would eventually come to pass in some form. Those trillions of data packets need help in being reassembled. The degree isn't worth arguing about, I was just letting the marbles in my head roll around.

I should have said something like "Does everyone know how much stuff in our lives requires synchronicity to work correctly?" and stopped there, but I've been up all night with a bad cold and therefore posted some good old internet nonsense. :confused:
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There's been a few other quotes that are pretty accurate, but here's one from someone who built out a data center in 2014...we'd be fine. Very, very few things need truly tight timing. Instead, the clocks internal to the computer are set regularly against the GPS signal. (True for my data centers and every other one I've been in contact with.) The computer's clock is regular enough to drive the system for months before the slew would cause real issues. The biggest issue that might be faced by most on-line companies would be in nearline and offline processing. Nearline processing requiring joins would need larger join window buffers. Offline processing doing timestamp matching for joins would need larger tolerances built in, resulting in uglier models. Nothing catastrophic, just poorer ML.

But it wouldn't even get to that. The time is fed to the hosts in the datacenter not from the GPS signal directly, but by NTP hosts in the datacenter timed against the GPS signal. If the GPS signal fails...they just revert to using NTP from NIST or one of the other trusted NTP hosts. They're already continuously matching against them anyway for redundancy.

I agree...navigation has far fewer fallbacks vs. static uses of the GPS signal.
 
Maybe we should just dig out the Sextant as a backup to GPS.

Yes I have navigated aircraft by sextant, watch, plotter whiz wheel and pencil. Need an Air Amanac and some HO249 volumes.
 
For eLoran to be a great back up system the users have to be willing to buy hardware or be mandated to buy hardware. Airlines will kill this bill.
 
MooneyDriver78 said:
A challenge to do that during IMC. Anyone have a sextant approach plate?


Tom
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Back when dinosaurs roamed, etc.

We flew with navigators with sextants and Air Almanacs and possibly chicken bones and tea leaves...

But during IMC, the navigators could perform an ARDA (Airborne Radar Directed Approach). The Nav would use the on-board radar to find the runway and give us an ASR type approach. All self contained. Now, this approach would have been a last-ditch effort to try and get the plane down on some concrete, its accuracy was very (VERY) dependent on the skill of the navigator on board, and even with the sharpest navs, it was definitely not what you would call precise by any stretch of the imagination.
 
Martin Pauly said:
I see the future in multi-constellation receivers with support for GPS, GLONASS, and maybe Galileo, too. Highly unlikely that all three systems could be taken out together, and they actually provide benefits at all times (e.g. more visible satellites for better geometry and position accuracy) as opposed to only being a backup.
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There have been flight tests by FreeFlight using a GPS/eLoran multi-input unit and the ground tracks were almost on top of each other.

Bob Gardner
 
Use of LORAN as a worldwide timing reference would be a poor choice ---- the groundwave coverage at 100 kHz would make the transmitter power requirements way too large. Individual LORAN chains were essentially independent of one another, although there were some chains that did have overlapping coverage areas, and did occasionally share slave transmitter sites. Synchronizing all the LORAN chains around the world (if they still existed) would require an independent time/frequency standard (like GPS) to which all the LORAN chains would need to synchronize.
Back in the 1950s and 1960s there was a lot of research done on finding an optimum frequency in the VLF portion of the spectrum for establishment of a single time and frequency station that would provide worldwide coverage. There were two frequencies that were identified as being best -- approximately 20 kHz and approximately 40 kHz. Such a station was never built, however the closest thing to it was the OMEGA navigation system. Eight stations located at various points around the globe provided worldwide navigation and time/frequency information. These transmitters operated in the 10 - 14 kHz range. The OMEGA navigation system transmitters were all held in phase with each other through the use of a portable cesium standard (literally a "flying clock") that was physically carried around the world (twice per year, I believe) to each one of the transmitters. Hewlett Packard manufactured these "flying clocks" --- they were a modification of their standard cesium beam oscillator that added a high capacity battery.
 
I used VLF/Omega for about five years. No moving map back in 1989, but the system was very accurate and the Trimble system had fuel computations built in...
 
davidgfern said:
Use of LORAN as a worldwide timing reference would be a poor choice ---- the groundwave coverage at 100 kHz would make the transmitter power requirements way too large. Individual LORAN chains were essentially independent of one another, although there were some chains that did have overlapping coverage areas, and did occasionally share slave transmitter sites. Synchronizing all the LORAN chains around the world (if they still existed) would require an independent time/frequency standard (like GPS) to which all the LORAN chains would need to synchronize.
Back in the 1950s and 1960s there was a lot of research done on finding an optimum frequency in the VLF portion of the spectrum for establishment of a single time and frequency station that would provide worldwide coverage. There were two frequencies that were identified as being best -- approximately 20 kHz and approximately 40 kHz. Such a station was never built, however the closest thing to it was the OMEGA navigation system. Eight stations located at various points around the globe provided worldwide navigation and time/frequency information. These transmitters operated in the 10 - 14 kHz range. The OMEGA navigation system transmitters were all held in phase with each other through the use of a portable cesium standard (literally a "flying clock") that was physically carried around the world (twice per year, I believe) to each one of the transmitters. Hewlett Packard manufactured these "flying clocks" --- they were a modification of their standard cesium beam oscillator that added a high capacity battery.
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I wonder if they took into account the calculated offset from time dilation due to travel from site to site.
 
DaleB said:
I wonder if they took into account the calculated offset from time dilation due to travel from site to site.
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Don't laugh...... the local oscillators in the GPS satellites have a very slight frequency offset to compensate for the difference in the earth's gravitational field between the surface and the altitude where the satellites are..... this is a consequence of General Relativity ------ the stronger gravitational field at the earth's surface makes time run slightly slow compared to time on the GPS satellites. See this link for more info:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5253894/
 
IK04 said:
I used VLF/Omega for about five years. No moving map back in 1989, but the system was very accurate and the Trimble system had fuel computations built in...
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My first job out of college was as a VLF radio engineer (civil service for the U.S. Navy) ..... I had the good fortune of being able to visit (and work on) many of the Navy's VLF radio transmitters and antenna systems. The group in which i worked actually built the very first OMEGA navigation system transmitter, and our engineers were the ones directly responsible for creating all the propagation correction tables that ultimately were used inside maritime and aircraft OMEGA/VLF receivers.
 
DaleB said:
I wonder if they took into account the calculated offset from time dilation due to travel from site to site.
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The accuracy of OMEGA was not good enough to make any errors due to relativistic effects visible.
 
Martin Pauly said:
I see the future in multi-constellation receivers with support for GPS, GLONASS, and maybe Galileo, too. Highly unlikely that all three systems could be taken out together, and they actually provide benefits at all times (e.g. more visible satellites for better geometry and position accuracy) as opposed to only being a backup.
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I have a little handheld Garmin 64s that does both GPS and GLONASS. So after the russians knock out the GPS constellation, I can rely on their system to navigate
 
I've been wondering about it a lot, ever since I flagged a GPS jammer on Walmart's web site as illegal. Walmart took it down the same day and said thank you.
 
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