US Coast Guard Intends To Kill LORAN-C 316
adaviel writes "LORAN (Long Range Aids to Navigation) is an electronic navigation system using low-frequency radio, used by many boaters (including me) before GPS. It has an approximately 200m accuracy and is a functional replacement in case GPS fails or the US implements selective availability in time of war. The US Coast Guard, part of the Department of Homeland Security, intends to turn it off starting February 8." This is in spite of $160M spent on modernizing LORAN stations over the past 10 years.
I am the Loran (Score:5, Funny)
-I'm just sayin'
Re: (Score:3, Funny)
Re: (Score:3, Funny)
and I speak for the Cs -I mean Seas
-I'm just sayin'
Are you going to pick yourself up by your pants and fly through a gap in the clouds?
Re:LISTEN, TERRORIST-COMMIE LOVERS !! (Score:5, Funny)
As trollish as your post is, I would wager that it is more than a little likely that LORAN is being turned off precisely because it is a beacon based system that selective availability cannot be implemented over. There is no way that LORAN could be used to provide positioning data to select parties.
Personally, I don't think this is a safe thing to do. Maritime equipment is notorious for being long lived. I would highly doubt that there are no boats that are still dependent on legacy systems. Well, I guess this is one way to ensure that they upgrade.
Feb 8:
First Officer: Captain! We've lost navigational systems!
Captain: Damn! That can mean only one thing. Arm photon torpedoes!
First Officer: Err.... we're a 32 year old fishing trawler and we don't have any...
Captain: Quiet! There's no time! Transfer engineering to the bridge and make sure we've got warp if we need it.
Re: (Score:3, Interesting)
>because it is a beacon based system that selective availability cannot be implemented over
You forget why selective availability was turned off.
During the years of Selective Availability, if you took your GPS receiver to a "known point" (like a USGS marker), you could adjust for the "fuzzing" (it wasn't a real fuzzing, it was just an offset) of the signal and get accurate readings anyway. This is known as "Differential GPS" and was widely used by people having an interest in using it (land surveyors, ci
Re:LISTEN, TERRORIST-COMMIE LOVERS !! (Score:4, Interesting)
The "new" version of DGPS is called WAAS (wide area augmentation system), which is where airports in the US will have local DGPS stations send their correction data to the WAAS satellite, and these corrections will be distributed to aircraft flying over the US for use as precision approaches (instead of the use of radio equipment at the end of runways).
Re: (Score:3, Informative)
The airport system is LAAS. WAAS is a general-purpose accuracy improvement system with signals broadcast from geosynchronous satellites. WAAS provides a 95% probability of 25-foot or better accuracy both vertically and laterally (with real-world measurements closer to 5-feet) for any compatible receiver over almost all of North America. It also provides an integrity guard; GPS signals that are out-of-spec can be invalidated in under 10 seconds.
LAAS uses a local VHF link to provide additional accuracy within
Re:LISTEN, TERRORIST-COMMIE LOVERS !! (Score:5, Informative)
Differential GPS made selective availability useless as a security tool.
No, DGPS is only useful if you have some way of of taking the pseudo-random variable offset recorded by the fixed GPS at the known point and sending it to the GPS you've stuck in the nose of your cruise missile or whatever. SA was a perfectly useful security tool. The real problems with it were twofold: First, the commercial applications for full-accuracy GPS were just too great to keep them locked up. Second, the military had such a difficult time procuring useful GPS units capable of accessing the encrypted full-accuracy signal that they gave up and acknowledged that most ground troops were walking around using commercial GPS rather than than the god-awful issue units and that they might as well have full accuracy.
Re: (Score:3, Interesting)
Exactly.
SA wasn't even used in the gulf war. Its unlikely ever to be used because so much relies on it, and a Euro system or a Russian system would make it pointless.
It was never all that great (the claimed accuracy is optimistic), the receivers are hopelessly expensive and all commercial use has, for all practical purposes, ceased.
Even during SA use periods, GPS tended to be more accurate anyway.
Re: (Score:3, Informative)
Re: (Score:3, Interesting)
Re:LISTEN, TERRORIST-COMMIE LOVERS !! (Score:4, Interesting)
Well they can simply turn GPS off (entirely or over certain areas) or introduce large-scale errors; since they don't control Galileo that's not an option and jamming is the only solution. And since jamming is not a precision tool it would be nice if jamming operations didn't interfere with the more selective control available for GPS.
They're probably also worried about unintentional interference from Galileo. Or jamming from third parties -- if someone starts jamming radionav systems it would be useful to know if they're targeting the EU or the US.
Re:LISTEN, TERRORIST-COMMIE LOVERS !! (Score:4, Insightful)
All it'll take to turn every one of the satellites in both systems into fried orbital junk is one little hiccup from the sun in the right direction. It is extremely foolish to turn off this system; once off, it will degrade even if left physically in place, and it won't be functional when needed -- which will be very suddenly.
The odds of non-satellite based navigation being needed eventually near 100%. Such solar "hiccups" have happened several times since the middle of last century. Some destroyed equipment on the ground -- and at those energies, nothing in orbit is likely to survive intact. That's not to say we've seen the worst the sun can do, either. Prior to the last century, high energy solar events had only non electronic technologies to induce current in; most likely weren't even noticed beyond a curious increase in corrosion here and there.
It never fails to astonish me how foolish our government can be.
GPS fragility (Score:4, Interesting)
On the contrary. The GPS constellation consists of fast-orbiting spacecraft. Period is about 11 hours. So all that must happen is an event that lasts 11 hours and has sufficient energy to do the job. The reserve sats (block IIR) orbit at the same rate; they'd be just as fried as the block II and block IIA sats.
For GPS to work, you need a minimum of three working sats within LOS of the antenna; the position fix is determined from the downward intercept of three spheres centered on the sats. Anyone who is depending on this, and suddenly loses it, may be in serious trouble. And it's not all that easy to whip out a sextant in the cockpit of an aircraft, or in your SUV (I'm really not sure how many expeditions actually carry a sextant, for that matter. I don't own one, and I do know how to use one.)
Here, take a look at this charmer, happened only 2 years ago: X-class flare [rense.com]. Pay particular attention to the duration.
Re: (Score:3, Informative)
Except, LORAN-C wa
Re: (Score:3)
A "nuke in space" wouldn't' do that much. Space is big and already filled with a wide range of radiation. The flash from a single nuke wouldn't blind too many sats for that long, and while it could certainly take out a satilite it wouldn't be able to take out many at once.
Re: (Score:3, Insightful)
Re: (Score:3, Interesting)
You'd be astonished how badly sextants work in fog or in a rainstorm.
In September 1923 in pre-Loran days, the US Navy ran seven destroyers onto the rocks at Honda Point in California. http://www.history.navy.mil/photos/events/ev-1920s/ev-1923/hondapt.htm [navy.mil] Those ships had plenty of sextants and navigators that knew how to use them. ... and they did not know where they were.
Re:I am the Loran (Score:5, Interesting)
Re:I am the Loran (Score:5, Informative)
The only people with anti-sat missiles are the same people who are operating the GPS satellites (the USAF); and the Chinese. (I suppose we can presume the Russians or Japanese could come up with something if they needed to, also.) And in both cases, the anti-sat missiles demonstrated were able to strike low earth orbit targets, in the range of a few hundred kilometers in altitude. GPS satellites are in medium earth orbits, which at 20,000km are considerably further away than any anti-sat missile ever tested has struck. Consider that the highest private rocket ever flown hasn't even reached orbit yet.
Detonating a nuke in space to disrupt communication is a video game plot device, not an actual strategy. It could theoretically disrupt or destroy nearby earthbound electronic chips, (taking out both GPS and LORAN-C receivers at the same time,) but at those distances even a big nuke would deliver little more energy to the satellites than a flashbulb. The birds themselves are separated from each other by distances of over 30,000 km, so even if your nuke got close enough to damage one it's safely distant from all of the others.
Space is really, really big. Mind-bogglingly big. These satellites are very, very safe right where they are. Not even James Bond could take out enough of them to be disruptive, but I'd suggest keeping a close eye on Chuck Norris.
Re: (Score:3, Interesting)
The best hope of hitting this kind of targets would be lasers. However, I think only USA has lasers that maybe approach the level of power and accuracy needed to hit a target floating very fast at several thousand kilometers "up there"
hmm (Score:5, Insightful)
Wow, I didn't know it was that inaccurate.
and is a functional replacement in case GPS fails or the US implements selective availability in time of war.
If the US implements selective availability of GPS, they can certainly also just turn off Loran-C.
Re:hmm (Score:5, Informative)
Yes the real answer seems to be a complimentary system, that isn't owned by the US. Fortunately, people realized this and the Galileo project was born. After some initial hissing on both sides, the US and EU have worked it out so they'll be compatible, and a single receiver will be able to get data from both GNSS systems. That way should one be turned off, or break or whatever, the other still works, and when both are up it should be even more accurate.
Unfortunately, Galileo is being run by the EU who seems to be able to make the US congress look positively efficient by comparison. As such there are currently 0 Galileo satellites operating. The whole system was supposed to be online by the end of 2008, however now they are targeting having a single satellite up by the end of 2010.
Thus as it stands, the US still does have complete control over GNSS systems.
Complimentary Systems (Score:5, Funny)
What a complimentary system sounds like: "My, what a nice position. That lat/long looks so good on you."
Of course, such a system would only be useful as a complement.
Re: (Score:2)
Re:hmm (Score:5, Informative)
Re: (Score:3, Funny)
Re:hmm (Score:5, Informative)
The U.S. is not the only country providing GNSS services. Russia has long had the GLONASS satellites; although their constellation has had some problems and does not currently provide 100% coverage over the globe (Russian coverage is at 100%, though, and I suspect U.S. coverage is near 100%.) Magellan makes commercially available GLONASS receivers, and I suppose others do as well. You can purchase dual GPS/GLONASS units, and the U.S. and Russia are in talks regarding bringing them to a common protocol so they'll be interchangeable if you have a receiver that picks up both frequencies. And the GLONASS program is receiving assistance from India, so there's more of an international approach to their program than just a Russian system.
I also know that China has their COMPASS satellites, but I don't know their status, or if there are commercially available receivers.
Re: (Score:3, Insightful)
"You know, I'm suspicious of that darn US government, they might arbitrarily turn off the GPS system at any time...so I'm going to use either the Chinese or Russian systems, because those governments have a FAR longer history of openness, tolerance, and a lack of autocratic behaviors than that darn America!"
Basically, if you believe that the Russians or Chinese aren't even MORE likely to turn off their systems when geopolitically convenient than the US, truly, you need
- a history lesson
- an understanding of
Re: (Score:3, Informative)
Indirectly, yes through taxes. GPS was a US military project. The military decided it would like to be able to accurately locate craft, personnel, weapons, and so on. There were some previous systems, like NAVSAT, but they were pretty inaccurate and of limited use (the Navy used it to help subs get a general position fix). They did all the R&D on it. When it was nearing final development stages, a Korean airliner got shot down by the USSR for straying in to Soviet air space and the president ordered tha
Re: (Score:2)
hell, 1km is good enough.
The submitter needs to learn how to use a sextant. They appear to get you about 500m accuracy.
Re:hmm (Score:4, Insightful)
200m is good for what ?
- Retrieve a crab/lobstrer pot ? ... No.. lemme tell you.. 200m is NOT good enough !
- Retrieve a Man Overboard ?
- Fetch a gill net ?
- Meet with a sister ship during a seine net operation ?
(No personal experience here - but my Old Man did !)
--Ivan
I don't know ask sig hansen (Score:2)
I don't know ask sig hansen
Re:hmm (Score:5, Interesting)
Actually, yes. When I was commercial fishing on a troller in Alaska we used Loran grid coordinates, spoken in Danish, to tell our brothers where the fish were. No one else could understand us. If we said "Over and out" the conversation was finished, but if we said "I'm off," that meant to change frequencies, tell how many King's you'd caught, and give the coordinates. Without the Loran our sneaky ways will have to be changed.
Re:hmm (Score:4, Interesting)
"Without the Loran our sneaky ways will have to be changed"
Come up with a list of 100 words. Danish, Esperanto, Klingon, or whatever. Assign numbers from 00 to 99. Read off your GPS coordinates using one word for every two digits. Save time by pre-defining large grids with special names to avoid having to read off more digits than necessary.
I've got notes around here somewhere on a more sophisticated version of that I was playing with for search and rescue use - not to conceal anything, but to be more efficient and accurate than reading strings of numbers. The words were simple, of a consistent number of syllables, phonetically distinct (long Hamming distance) and with multiple lists you can make it tolerant of transposition of words. The idea was for the encoding to be done on a GPS receiver - you wouldn't need to do it manually.
Re:hmm (Score:5, Funny)
Re:hmm (Score:5, Insightful)
200m is good for what ?
- Retrieve a crab/lobstrer pot ? - Retrieve a Man Overboard ? - Fetch a gill net ? - Meet with a sister ship during a seine net operation ? ... No.. lemme tell you.. 200m is NOT good enough !
(No personal experience here - but my Old Man did !)
--Ivan
Sit in the middle of the ocean and turn off GPS. Perhaps you'll quickly see the value of "good enough". I'm all for a backup plan, and a backup plan to the backup plan, especially if we can avoid pissing away a $160M investment.
That's NUTS (Score:4, Insightful)
Hear hear.
What bugs me is this statement from the Coast Guard:
They're studying whether they NEED a backup so they'll turn off the only current backup before the study is finished or (if required) the replacement backup is deployed?
That's NUTS! What happens if GPS is compromised between the decommissioning of LORAN-C and the deployment of the hypothetical replacement?
Also: Why deploy a DIFFERENT backup and make all the users buy ANOTHER device when they ALREADY HAVE LORAN-C equipment? Even if the equipment was FREE the cost of obtaining it and installing it, multiplied by the number of users, would be astronomical. Unless something damned cheap, built off some other deployed tech, is designed, the cost of maintaining LORAN-C would be a drop in the bucket.
Re: (Score:3, Insightful)
You're in the middle of the ocean in a storm. Or even better, you're NOT in the middle of the ocean in a storm, and want to know if you can drift a couple more hours before hitting some rocky island or not.
Having even 1 kilometer accuracy is very good in this situation, not to mention 200 meters. On the other side, in this case, 10 meters accuracy would be overkill.
Re:hmm (Score:5, Informative)
Well if you were in the middle of the ocean, you probably wouldn't get a LORAN-C signal at all so your backup really isn't a backup. Check the LORAN-C coverage maps, anywhere outside the Caribbean, North Atlantic and North Pacific simply can't get any fix from LORAN-C signals (so if you're south of the equator you're probably SOL). Anywhere out of sight of coasts doesn't really get a great signal and has a fairly poor resolution.
http://en.wikipedia.org/wiki/OMEGA_Navigation_System [wikipedia.org]
Thats what the Omega system was for. Operated from 1971 to 1997. For reasons unknown the USAR put me thru a correspondence course on the Omega system in like 1996 (1995?). Omega had worldwide coverage. Its interesting that Omega could be heard with those "ELF" receivers as the carrier frequencies were in the audio range, made it quite annoying to listen for "whistlers". Its interesting that LORAN relies on chains where a master TX sends a pulse, then the remotes send another as they hear the master, so each chain has a single point of failure. Omega on the other hand had each station send a different pattern of tones, so you'd sync to each pattern/station, then measure the relative time (and/or phase) difference between them to get the ratio of distances to each station, so no single point of failure. GPS is basically Omega with the following differences, about a zillion times higher frequency, a much fancier spread spectrum modulation than the four tone Omega, and of course the GPS satellites move...
http://en.wikipedia.org/wiki/Transit_(satellite) [wikipedia.org]
The russian transit sat equivalents are still up there and transmitting as of a few years ago. All the systems generally transmitted two data carriers very close to 200 and 400 MHz. Receivers measured the ratio of frequencies, thus figuring out the doppler shift directly without needing an accurate oscillator on the ground. Doppler hits zero when the satellite is overhead, and its no great task to calculate and distribute plots of where a satellite is directly overhead at any moment. That gives you only one fix, but you can also measure the rate of change of the doppler effect, giving you quite accurately how high the satellite was above the horizon, that gives you a 2-D position.
LORAN has better *repeatability* than *accuracy* (Score:5, Interesting)
At least my recollection is that while the absolute accuracy of LORAN isn't nearly as good as GPS, it actually had better repeatability (i.e. the ability to return tomorrow to that fishing spot you found today) than at least pre-DGPS/WAAS GPS did.
Today's modern GPS systems and supplemental accuracy aids probably make this moot, but it's a major reason why LORAN has survived as long into the GPS era as it did.
G.
How about (Score:5, Insightful)
200m is good for what ? ... No.. lemme tell you.. 200m is NOT good enough !
- Retrieve a crab/lobstrer pot ?
- Retrieve a Man Overboard ?
- Fetch a gill net ?
- Meet with a sister ship during a seine net operation ?
How about:
- Find a port when you're somewhere random in an ocean?
I'd be HAPPY to live with a 200 meter error if I'm trying to, say, get the Golden Gate Bridge to show over the horizon in time to beat a squall line into San Francisco Bay. Or to know if I'm FAR ENOUGH OFF the west coast of North America that I won't be blown onto it before a storm I can't outrun blows by.
Re:How about (Score:5, Informative)
[...]Find a port when you're somewhere random in an ocean?
LORAN is pretty much useless for this. What almost everyone here seems to be missing is:
LORAN coverage is very limited.
There's e.g. none at all on the southern hemisphere, and in the northern it isn't much more than
a coastal navigation help either.
Have a look at the map [wikipedia.org].
LORAN is in no way a useful backup for GPS except in a very small part of the oceans.
Re: (Score:3, Interesting)
LORAN coverage is very limited. ... Have a look at the map.
LORAN is in no way a useful backup for GPS except in a very small part of the oceans.Look closer at that map.
Take a closer look at that map. It goes out a goodly distance from the coasts.
They say that, in an airplane, you can do anything you want as long as you don't do it close to the ground. Much the same is true for boats and the shore.
If you're really far out in an ocean you can get back to a continent by sailing east or west until you pick u
Re: (Score:3, Insightful)
200m is good for what ?
Not hitting St. George Reef in the fog.
Re: (Score:3, Interesting)
As long as you have a decently accurate clock [nasa.gov], you can get a lot closer than that without any externally-dependent navigational system.
Re: (Score:3, Interesting)
500m accuracy for sextants seems unrealistically good to me. My experience is approximately 2km in good conditions and with an accurate clock available. But even that is good enough for navigation.
Re: (Score:3, Insightful)
Does anyone else see the irony? in using LORAN US implements selective availability, when LORAN is only accurate to 200m ?
Selective availability was a (currently disabled) feature of GPS that adds intentional errors up to 100 meters / 328.08 ft to publicly available GPS signal...
Before SA was turned off in 2000 the typical SA errors were 32ft horizontal, 98ft vertical.
SA is easily defeated using Differential GPS [wikipedia.org].
One thing to note about LORAN, vs GPS, however is: GPS is basically owned by the United
Re:hmm (Score:5, Informative)
Are you always this paranoid about the U.S. government? Seriously, the Russians have had their version of GNSS flying for 35 years, and you can buy a completely non-American GLONASS receiver that will give you the same data as an American (made in China, of course) GPS receiver. We know full well that we don't have a monopoly on global navigation.
They are shutting LORAN-C off because it's expensive to maintain a separate system, especially one that is not nearly as accurate as GPS, and is at risk of terrestrial attack (a determined terrorist group could easily destroy a critical LORAN-C tower, but the same group does not have physical access to the GPS satellites.) In addition, its consumers are not widespread, and are already using GPS for their primary navigation systems.
You should think before you make up bogus conspiracy theories. They make you look kind of crazy.
Better performer in poorer RF conditions? (Score:3, Interesting)
...They are shutting LORAN-C off because it's expensive to maintain a separate system, especially one that is not nearly as accurate as GPS, and is at risk of terrestrial attack...
But -- isn't the Loran C low frequency operation better able to punch a signal through periods of poor RF "weather"? During heavy solar storm activity (sunspots, peaking each 11 years) I hear it's sometimes kind of hard to get signals through, especially the S or K band stuff used for satellite communications. I remember during the Pioneer satellite days that it was sometimes quite a job for us to pull the signal out of the noise (clever use of FFT mostly). Satellites don't have huge power budgets. Lar
Re: (Score:3, Insightful)
It ain't sexy cause Obammy's trying to squeeze blood out of a stone to shore up the deficit
Re: (Score:3, Informative)
The U.S. has full control over the LORAN-C transmitters in the U.S. too. Hence their ability to shut them down.
And those countries can continue to use LORAN within their own borders. The U.S. has no power to turn those off.
Re: (Score:3, Informative)
If the US doesn't like being part of an international system, then why keep a woefully obsolete, far less accurate system running into 2010? It's like complaining that a new Dell doesn't offer built-in floppy drive. One person's redundancy is another's dead weight. There is still GLONASS running now, even in a weakened state it has to be better, and hopefully Galileo will be up soon enough.
Re:hmm (Score:5, Interesting)
200m is the absolute accuracy (and is a bit pessimistic). The repeatable accuracy is much better.
That is, if you sail into a port's harbour channel and save that as a LORAN-C waypoint you will typically be able to get back to that same spot within 20m or so easily.
Re: (Score:3, Interesting)
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Besides, GPS with S/A is accurate to 100m, still better than the figures given for LORAN-C.
Re:hmm (Score:4, Interesting)
Back in the day, I actually rigged up a Loran system and a surplus Compaq Plus luggable computer in my car, and wrote a program in QuickBASIC to log lat/long data points while driving back to college from vacation. Just to see what it would look like, I drove completely around a cloverleaf interchange (four 270-degree turns), and continued on. When I got where I was going and ran the data through a really cheapo plotting program I wrote, I could clearly see all four loops (some a little flattened, probably more due to the 1-second time resolution than anything.)
Granted, this was in the middle of nowhere (low noise), at night (nice propagation), with a long whip antenna on the top of the car -- but it was still impressive for Loran-C. (And yeah, I know it would be a piece of cake for any half-decent GPS receiver.)
As for selective availability, I think this could be implemented over Loran -- although Loran's repeatability without modifications is probably no better than the ~50m accuracy of GPS+SA...
Re: (Score:3, Funny)
Your friend wasn't the navigator on the USS San Francisco by any chance, was he? ;)
Loran-C? (Score:4, Funny)
What's Loran-C some strange C dialect? Did Loran-C++ eat its lunch or something.
Re: (Score:2)
Well.. Guess Loran isn't object Oriented.. Functional is all that's needed for Loran.. (Latitude.. Longigute.. That's all you need to know really)..
And yes - it's just a troll troll..
(Although a professional wouldn't really care about that !)
Costs and benefits (Score:5, Insightful)
There's this thing called the Concorde Fallacy [wikipedia.org] that is relevant here. It doesn't matter how much money you spent, all that should matter is anticipated future costs and benefits. And I think for a 200m redundant navigation system, future costs >> benefits.
The name Bowditch comes to mind (Score:2)
Of course you would need an accurate clock and maybe a sextant?
As for the comment on "only 200 meters", that might not even be all the way to the other end of the ship.
Re: (Score:2)
Humph...
AFAIK, Loran-C was only for coastal operations.. Who would operate a 600ft ship in coastal waters ?
--Ivan
Re:The name Bowditch comes to mind (Score:5, Funny)
Sailors, I guess.
Comment removed (Score:5, Interesting)
Comment removed (Score:4, Informative)
Last time... (Score:4, Insightful)
Last time I saw a LORAN-C device was on my family's sailboat that we used to motor-sail to Alaska from Washington through the Inside Passage. That was 1990. It wasn't much use even at the time. Radar and charts were much more helpful with navigation. I haven't even heard mention of the term LORAN-C for a very long time. I don't think most vessels have a LORAN-C receiver installed anymore. Maybe big ones, but not the hundreds of thousands of small to medium size vessels. Hard to justify keeping it running if nobody is using it. What's the benefit if almost nobody owns the necessary hardware anymore? Just playing Devil's Advocate. I'm sure it's still useful to somebody, somewhere.
Cost/benefit (Score:4, Funny)
LORAN (Long Range Aids to Navigation) is an electronic navigation system using low-frequency radio, used by many boaters (including me) before GPS. It has an approximately 200m accuracy and is a functional replacement in case GPS fails or the US implements selective availability in time of war.
Wait -- they're talking about decommissioning a redundant technology and relying on one that the military spends millions on and is mission-critical to its functioning (and thus in no danger of suddenly going offline)? Why is this sudden outbreak of common sense being maligned? I wish our government did this more often!
One down, many more to go. (Score:5, Informative)
There is absolutely no use for Loran C. You currently have the following systems in place backing each other up. Many cheaper and better. In fact, many of these most likely will vanish soon.
1. GPS, LAAS, WAAS, DGPS
2. Galileo, EGNOS,
(as well as GLONASS and Baidu)
3. Inertial
4. Visual navigation (computer with terrain sensors, including sonar and radar)
5. Also VOR, DME, ADF, NDB, ILS, TLS, MLS, Marker beacon
with the final fallback
6. Old fashion navigation with compass, light houses, sextant, chronometer etc.
Re: (Score:2)
Well, pilots of small aircraft (myself included) found it the best, cheapest nav choice prior to GPS. Dunno if it's worth having as a fallback in case GPS is degraded or taken offline or not. Maybe I'm just nostalgic because being able to navigate "Loran Direct" was so superior to flying from VOR to VOR.
Re: (Score:2)
TLA WTF IMO, YMMV.
Re:One down, many more to go. (Score:4, Informative)
Galileo
There are no operational Galileo satellites in orbit yet.
(not that it makes any of your other points less valid, just a factual correction)
Sunk cost (Score:4, Insightful)
This is in spite of $160M spent on modernizing LORAN stations over the past 10 years.
Econ 101: don't make decisions on the basis of sunk costs.
More USCG and DHS waste (Score:2)
A drop of piss in the bucket (Score:2)
Do you know how many times that the government shits out every day on projects they know will probably never see the light of day? It's so bad at this point that I find 160 million into a 10 year old functional project (open to the public, no less) to be the bargain rate.
Satellite versus groundstation (Score:3, Insightful)
station tahoe pipeline will be gone (Score:2, Informative)
$160M over 10 years? (Score:2)
$16M/year is nothing to the government, they've just been keeping it on life support for 10 years. Even if SA is turned back on, GPS will be accurate enough for commercial navigation and the system proven reliable enough. Let LORAN-C pass.
I'm surprised this is still around (Score:4, Interesting)
Kill LORAN? (Score:4, Funny)
The Coast Guard is going to "kill" LORAN? This choice of words worries me. What if LORAN decides to strike first, out of self-defense?
"LORAN", "SKYNET", both are short words with an 'N' in them. COINCIDENCE? I think not!
steveha
What, it's still there? (Score:5, Interesting)
I've been a sailor most of my life. We haven't used Loran C seriously for almost two decades. Most boats don't even have Loran receivers any more. It's GPS all the way whether you are a casual sailor or a commercial ship captain. In fact, large commercial ships are required to use GPS and special transceivers these days (the boater's equivalent of GPS-based aircraft systems). If backup matters one could pack a RDF or maybe even a sextant, but frankly GPS has not failed even once from the day it became available to boaters. Besides, Loran C pretty much only works near the coastline of major industrialized nations (or did)... it wouldn't be all that helpful if you were lost at sea.
The coast guard should have abandoned Loran C years ago.
-Matt
200 Meters sounds pretty good compared to... (Score:4, Interesting)
So, lets say you need a 10 Mhz Reference (Score:3, Interesting)
And your GPS satellites got blasted out of orbit or a solar storm wipes out all of those satellite resources?
Your SONET networks and cell phone stuff are gonna need it. Your 8-VSB exiter may as well. Single Freq. Networks.
Where do you get an accurate reference from?
WWV? I haven't seen anything other than a GPS reference at any telco facility/cell site. If there ever is a loss of GPS, it's gonna be interesting.
The end of an era (Score:3, Interesting)
It's the end of an era I guess. This story throws me back to 1964, wandering the North Atlantic aboard HMSS Hudson, doing marine geophysical surveys.
When it came to positioning, we left nothing to chance; we had the requisite equipment (pre-computer), tables and charts for LORAN, DECCA, CONSOL and the brand-new, edge of the technical envelope, VLF. Sometimes we used a few of them together, with transparent overlays giving a very small polygon containing, somewhere within it, our little ship. We liked to brag that we could pin down our position within its length.
One of my favourite duties was radar watch and navigation, especially late at night, lights dimmed, phosphorous glow from both the radar screen and the froth on the waves ahead. Transferring readings from the radios and charting our course made me an integral part of the process, acutely aware of the immensity of the ocean around us and challenged to keep us from losing our way. I can still smell the mixture of diesel, coffee and ammonia (from the weather fax machine) that permeated the bridge.
Now, with the retiring of LORAN, it's finally all gone, replaced by an LCD display your grandmother can use. Sad.
Loran and Decca (Score:3, Insightful)
Loran is pretty similar in capabilities and techonology to DECCA, which was widely deployed in Europe. There are some differences in the implementation, but both gives roughly the same precision. The Decca system up here was turned off 1999/2000, as it wasn't considered cost efficient anymore compared to GPS. Decca as I remember it had a number of rather glaring flaws when using it for navigation:
1: Low precision (several hundreds of meters)
2: Varying precision (Depending on the distance and position compared to the masts)
3: Initialization problems (had to be started at a know position, entering the wrong starting location would give you incorrect data)
4: Unwieldy equipment
5: Energy consuming
6: General user-unfriendlyness (you had to be an engineer and take a 2 week course to figure out the equipment we carried on the ships)
Frankly I don't see the need for Decca anymore. If you are in a ship large enough to use Decca you have DGPS anyway. If GPS Is knocked out you go by Radar. If GPS and Radar are knocked out you most likely don't have any Decca system working.
On the navy side it's obviously nice with passive navigational aids (unlike Radar that makes you a neat target). However, a large antenna that has to be in a fixed position is not exactly a hard target for an ARM (Anti-Radiation Missile)... Which means the navy trains to navigate without such aids anyway.
Decca was an impressive system, but it's no longer competitive. Like analog TV we can use the wavelengths for better things. I am pretty sure the situation is the same with Loran.
Kinda Sad (Score:3, Interesting)
I've never used it on a boat but I went flying with another pilot once who had a LORAN unit installed in a Kitfox. I didn't even know what it was at the time, but as he explained it, it was much cheaper to install than a VOR receiver. We did a fair amount of flying in Florida navigating using that unit.
I know that with the prices of handheld GPS (for aviation, boating, and everything else) coming down a lot of such technologies may be shut off, but it still seems a bit sad to me. I love GPS and it certainly is easier to use, but I'd like to see some of the older technologies maintained at least as backups.
Re: (Score:2)
I believe the GPS III [slashdot.org] constellation will be the modernization effort you're looking for.
Re: (Score:2, Interesting)
Re:Idiotic. (Score:5, Insightful)
No country wants to maintain them? What are you smoking?
The GPS system is launched and operated by the US Air Force, first and foremost for US military activities. It wasn't some magical pan-national committee that put the satellites into orbit and built the ground stations. And the USAF maintains them and modernizes them. If GPS goes offline, all those fancy GPS guided weapons go offline too.
As for redundancy... put two GPS receivers on your ship.
Re:Idiotic. You got that part right at least. (Score:5, Interesting)
"This is especially idiotic considering GPS satellites that are currently in orbit are beginning to fail, and no country wants the responsibility of modernizing them, or repairing them."
Okay...
1. The DOD depends on GPS and matains the network. So what are you talking about countries wanting to take responsibility for the GPS network? The US DOD does.
2. You do not repair or modernize GPS satellites... You replace them.
3. GPS is going to keep working until it is replaced with something else or the US stops being a nation.
"Further, what if a GPS receiver goes offline on a ship?"
You use the backup? You don't really think that a ship would only have one do you?
The reason to keep both was that many operators spent a lot of money on Loran and GPS was expensive. Now GPS is cheaper and more reliable than Loran.
Your arguments are along the lines of "We should keep paying for hitching posts on our streets so we can keep horses as a back up for cars."
Re: (Score:3, Insightful)
Re: (Score:2)
Except the US.
So what happens when GPS doesn't work anymore?
Given the military use of GPS, that's unlikely.
Further, what if a GPS receiver goes offline on a ship?
If A GPS receiver goes offline on a ship, you turn on any of the leventy-dozen other GPS receivers on board, including the handheld you bought for a hundred
Re: (Score:2)
[[citation needed]] - GPS sats are failing
Re: (Score:3, Interesting)
In my pilot weather briefings, I routinely get notice that one of the satellites (GPS-25, I think) is out of service, and I think GPS-30 showed up in a briefing recently, too.
Re: (Score:3, Informative)
Re:Accuracy (Score:5, Interesting)
SA made GPS accurate to 10m.. With the "SA" feature disabled, you're down to 2m... And with Satelite enhancements, it's more like 20cm !
But that's irrelevant.. Because SA was intended to disable any enemy force from using GPS for accurate positioning - until they realized D-GPS (Differential GPS) made the whole point moot (you take a reference point - you send the signal to the receiver - And therefore - the receiver can deduce the SA introduced clock error - because now you have a ref point .. And believe it or not - it is a United Stated Uniform service - the US Coast Gard - that came up with it to overcome the artificially introduced uncertainty).
However, the military still keep exclusive use of the 1Mhz band (with the 10Mhz being public) - for the only purpose of being able to make real time measurements on tropospheric distortions - so - what happens - is that the military can make 1m accurate reading WITHOUT sat aids.
Re: (Score:2, Insightful)
"Thousands, possibly hundreds of thousands of people die in Haiti due to a massive earthquake and we're talking about freaking LORAN-C??
Get some PRIORITIES!"
Haiti isn't worthy of discussion. It's tragic, there are lots of tragedies, but that a thing is tragic doesn't make it worth discussion in a tech forum.
Haiti is BTW a hopeless case, the people who live there maintain it so, and their choices aren't my concern. Go to an appropriate forum to whine about Haiti, or go there yourself ("PRIORITIES!") and help
Re: (Score:2, Insightful)
Excuse me, fella. This is /., not the Red Cross. Do you really expect us to discuss news stories on here? Why not Reid's remarks about Obama, the Massachussetts senate race, or what ever will Conan O'Brien do now, or your mama's corn bread recipe? Because they are largely irrelevant. You wanna talk earthquakes, go where they are discussed.