rwessel
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New Obama Budget Kills Loran

Thu May 07, 2009 4:11 am

Apparently as part of an effort to save $17B, $36 million will be saved by killing the Loran-C system.

http://money.cnn.com/2009/05/06/news...bama_budget_cuts/index.htm?cnn=yes

(Note the CNN article doesn’t quite identify Loran by name, but other sources do.)

Personally I think it's a shame, and that Loran makes an excellent local backup to GPS, with wildly different operational parameters, for very, very little money.

The lack of a clear commitment to Loran has undoubtedly led to (additional) reduction in usage. After all, why would you add a Loran receiver to your navigation device if Loran had an uncertain future.

Perhaps the presence of Galileo and/or Beidou will mitigate the loss/missed opportunity somewhat, although they have many vulnerabilities similar to GPS/Navstar.
 
Soku39
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 6:17 am

I am in complete agreement. No one ever stops to think about what happens if the satellites fail, because it could never ever happen (sarcasm).
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wilco737
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 7:21 am



Quoting Rwessel (Thread starter):
Apparently as part of an effort to save $17B, $36 million will be saved by killing the Loran-C system.

I thought there are not operational Loran- C stations left. That's what I've been told 8 years ago at flight school.  Confused

We don't even have a Loran- C receiver on board. Only GPS, IRS, conventional navigaion (VOR, DME, NDB).

wilco737
 
rwessel
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 8:17 am



Quoting WILCO737 (Reply 2):
I thought there are not operational Loran- C stations left. That's what I've been told 8 years ago at flight school.

We don't even have a Loran- C receiver on board. Only GPS, IRS, conventional navigaion (VOR, DME, NDB).

Yeah, I've heard that kind of error from people who should know better before. Clearly a part of the problem - of course you're not going to try to use a system, or even have any interest in it, if you think no longer exists.

No, Loran is (technically) perfectly healthy, and the proposed eLoran upgrades (which would be fairly inexpensive - and currently being implemented in the UK and Western Europe), would bump accuracy to the 8-10m range.

Part of the problem is that it's pretty cheap to run, and is just not as sexy as satellites. Heck, the proposed cut will save $36m next year, and $190m over the next five. $190m won't even buy you a single GPS bird, much less get it launched.

It's really a shame. The system is technically so different from GPS, that's it's hard to imagine something taking both systems out at once. And adding Loran support to a typical GPS receiver is pretty trivial. You need all new analog/RF stuff, but nothing that's even slightly complex (how hard is it to build a 90-110KHz receiver?), and there's far more computing power than you need already built into any GPS receiver. And as a sanity/health check for the GPS, it would be excellent. And as a backup, you might not be able to fly a complete approach with (basic) Loran, but it'd reliably get you close enough that you could shoot a "200-and-a-half" manually.
 
nomadd22
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 11:55 am

I first heard of the impending death of Loran when I was working on it in 1980. I've heard about it a dozen times since then. Every time a few congressmen make a deal to get the item stripped. I'll believe it when all the stations have been converted into homes for wayward seabirds and the trnasmitters are on ebay.
Anon
 
DingDong
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 2:20 pm



Quoting Nomadd22 (Reply 4):
I first heard of the impending death of Loran when I was working on it in 1980.

Yeah, ditto. I think Mark Twain once had a relevant quote regarding its death. Wink

Well, an option might be to deploy the newer eLORAN infrastructure which would nicely dovetail as a backup role for a GNSS system (NAVSTAR GPS, Galileo, Beidou, GLONASS, etc...) while maintaining contemporary relevance -- and thus, continued long-term funding for it. No bucks, no Buck Rogers, after all.
DingDong, honey, please answer the doorbell!
 
roseflyer
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 3:35 pm

A lot of people are defending Loran, but who here has actually used it as a navigational tool apart from being taught how to use it in flight training?

I think the rumors of budgets cutting things like VORs or ADFs is a much bigger concern since thousands of GA aircraft rely on those two navigational tools and do not have GPS or Loran. I know I have never used it on any flights. I have been in planes equipped with it, but haven't even thought of using it on flights. I've just used GPS with VORs as my backup.
If you have never designed an airplane part before, let the real designers do the work!
 
Soku39
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 3:59 pm



Quoting RoseFlyer (Reply 6):
A lot of people are defending Loran, but who here has actually used it as a navigational tool apart from being taught how to use it in flight training?

It's just a good backup to the satellites. It doesn't get much easier than just spitting out a lat/long and plotting... I mean seriously it's just really easy to use.

Quoting RoseFlyer (Reply 6):

I think the rumors of budgets cutting things like VORs or ADFs is a much bigger concern since thousands of GA aircraft rely on those two navigational tools and do not have GPS or Loran.

The thought of them getting rid of VOR's completely makes my skin crawl... more so than the lack of Loran.
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pilotpip
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 5:08 pm

I've never flown a plane equipped with Loran. The plane I fly now isn't authorized to navigate via anything other than long range nav except when doing an ILS.

LORAN really has a bigger effect on marintime navigation but even they are switching over to GPS in droves.

As far as NDB, it's no rumor. They're going away pretty fast. By the time I was instructing two years ago I had to go out of my way to find a working NDB approach. VOR's won't be going away any time soon despite the FAA's desire to eliminate them.
DMI
 
KELPkid
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 5:38 pm

Talk about a lack of long-term vision...

Sure, satellites are great. The GPS system works very well.

The FAA loves it, because it comes out of the Air Force's budget, not the FAA's. I've heard the Loran system comes out of the Coast Guard's budget.

If the Air Force ever got into a budget crunch, would they start billing civilian users for their "fair share" of the system (in fact, I'd estimate that nowdays, civilian users are probably about 90% of the users  Wink )?

In the grand scheme of things, the Loran-C system is much cheaper to maintain. There will be a time where keeping 24 satellites + 3 operational spares on orbit will start to weigh us down economically (especially when the said satellites start reaching the end of their operational lifecycles). It really was, and is, a "Cadillac" (maybe a Mercedes Benz or Rolls-Royce for our non-North American readers) solution, in a country where Chevy costs are better...

I, for one, was sad to see Loran lose to GPS in the RNAV wars of the early 1990's. It was for the reasons that I outlined above. Sure, GPS gives you altitude info, too, but Loran-C was really a more long-term solution.
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DescendVia
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 6:34 pm



Quoting KELPkid (Reply 9):
I've heard the Loran system comes out of the Coast Guard's budget.

Yeah the Coast Guard maintains it and provides NOTAMs to the FAA about it.

Quoting KELPkid (Reply 9):
Sure, GPS gives you altitude info

Off subject but really GPS altitude is not used for navigation unless its WAAS augmented. Raw Baro-GPS altitude is only for RAIM predictions if the required number of satellites are not visible.
 
roseflyer
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 7:14 pm

But why keep it if no one uses it? Just as a backup in case? VORs, dead reckoning and GPS should be enough.

GPS is not going away. It is used in everything. Not just air force or navigation. The same satellites are used for tracking systems used everywhere in the economy. Even Chevys come with optional navigation installed.
If you have never designed an airplane part before, let the real designers do the work!
 
nomadd22
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 7:34 pm

Once Galileo is up and can back up GPS, there will be less justification for Loran to stay active.
Anon
 
roseflyer
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 9:10 pm



Quoting KELPkid (Reply 9):

In the grand scheme of things, the Loran-C system is much cheaper to maintain. There will be a time where keeping 24 satellites + 3 operational spares on orbit will start to weigh us down economically (especially when the said satellites start reaching the end of their operational lifecycles).

Do you honestly think GPS will be phased out because it is too expensive? Should we keep an older generation system working just because it is cheaper? GPS is used in far more applications. I don't see it going away.

If satellite television has been made cost effective, how will GPS disappear? GPS replaced less capable systems. Satellite television on the other hand tried to replace cable, which technically works better than Satellite.
If you have never designed an airplane part before, let the real designers do the work!
 
A342
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 9:22 pm



Quoting RoseFlyer (Reply 11):
But why keep it if no one uses it? Just as a backup in case? VORs, dead reckoning and GPS should be enough.

It does provide a backup to GPS and IRS over oceans where you don't have VORs, DMEs or NDBs.
Exceptions confirm the rule.
 
roseflyer
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RE: New Obama Budget Kills Loran

Thu May 07, 2009 10:15 pm

These are the types of decisions I make every day as an engineer working on aircraft designs. You don't keep something just because it is inexpensive or is used for peace of mind. I would expect data to be tracked. How often is Loran used? Have there been any aircraft where all other navigational tools have failed so that Loran was the only backup available? If so, what would have been the consequence if it did not exist? Every one of those questions can be quantified, even the last one. If it does not have a payback, then it should be eliminated. If it does have a payback and the beliefs fo those here are that it is needed, then it should be kept. I deal with people saying that they really want to keep relics of the past just because they want to keep them.

With that said, Loran had a purpose, but has it been replaced adequately or are we looking at a serious safety issue with it going away?
If you have never designed an airplane part before, let the real designers do the work!
 
DiamondFlyer
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 12:47 am



Quoting RoseFlyer (Reply 11):
But why keep it if no one uses it? Just as a backup in case? VORs, dead reckoning and GPS should be enough.

Because, if the FAA has their way, the VOR's are going away (unlikely, IMO). However, in the event of a solar event, with no VOR's, what would be used as primary navigation? With nothing else but GPS, the only choice is to send up new satellites, probably a 5+ year proposition. With LORAN, you could just install a receiver in each aircraft in a short time, and be back in a limited business. Seems like keeping LORAN around is a good deal, considering the relatively low costs associated with it.

-DiamondFlyer
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rwessel
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 1:41 am



Quoting RoseFlyer (Reply 11):
But why keep it if no one uses it? Just as a backup in case?

That is the problem.

My (and a lot of other people's) issue with relying on only GPS is that it's a single system, with a number of vulnerable points, from the limited number of ground stations, to the very low signal strength (jamming, or even faking, the CA signal over a fairly large area is within the reach of anyone with a couple million to spend), and is a system that will require years to rebuild should a catastrophe happen - there is simply no fast way to build satellites and launch vehicles.

Loran is very different, in many ways. You could blow up every Loran transmitter in every chain on the continent, and with a somewhat crash program, have it all rebuilt in a six months – the most difficult part would be rebuilding the antenna towers (which is hardly high tech). It's also harder to jam over a wide area (the power requirements are much higher, even if the signals are simpler), and given that it works on total different sets of frequencies, and has seriously different vulnerabilities, having both makes a catastrophic failure much less likely, even in the face of deliberate attack. In fact having both makes a deliberate attack against either system less likely, because it will accomplish less.

That being said, the problem is that almost no one is using Loran as a GPS augment/backup system now. And why would anyone bother? The regulators seem intent on living with just GPS. And then Loran has been at death's door (politically, not technically) for a couple of decades now.

Loran *could* be used as a backup for many GPS system, and for very little cost to the user. You might not bother to add a Loran receiver to the GPS in your car, but the one in your airplane or boat, where you can't just pull over at the next gas station to ask directions, has a critical dependency on the continued operation of the navigation system for a period of hours or days. Loran *could* fill that role, and as I said, for very little money. It might not quite be the system I'd design for that purpose from scratch, but it pretty close to what I'd want, and it already exists.

I am *not* comfortable with the level of redundancy we'd have if we put all our eggs in the GPS basket. While things could be done to enhance GPS in that regard, WAAS and LAAS (or the European EGNOS) although they address specific issues with some uses of GPS, do not address those issues. Some of that will be addressed as some of the other satellite nav systems go online (or in the case of GLONASS*, if it ever gets put back together), but they all present similar sets of vulnerabilities, if at least somewhat disjoint.

Purely from an engineering point of view, a radically different backup/augmentation system (and getting both GPS and eLoran will get you a better and more reliable fix - straight Loran-C would improve a good GPS fix only trivially, although the much stronger signal allows Loran reception in many places with poor GPS reception) is a good idea, since you simply don't get the common failure modes. Consider that many FBW aircraft have at least partial control systems run with cables (admittedly that changing), or that hydraulically powered controls can have trim-tab "powered" backups, or a RAT in case all the real generators go offline.

But if nobody uses Loran, it will go away. The shame is that GPS, wonderful though it is, *needs* more backup, and Loran can provide that for a very small cost to the operators needing that additional level of redundancy. And it's a pretty darn cheap system to provide too! After all, it already exists. But if we all decide that GPS, perhaps backed up by Galileo or Beidou, is secure enough, then Loran has little reason to continue to exist.


*I didn't mention GLONASS upthread due to my lack of confidence on that issue.
 
KELPkid
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 2:37 pm



Quoting RoseFlyer (Reply 13):
Do you honestly think GPS will be phased out because it is too expensive?

Let me ask you how much effort, Mr. aerospace engineer, goes into building a Delta II rocket?  eyebrow  Sure, space exploration has its place, and I'm glad our country is a leader in that. However, in the end, having to do a space launch on a very large, expendable launch vehicle every time something happens to a satellite is not a good investment in resources...considering that the oldest GPS satellite on orbit now was launched during my first semester of college (November 1990 for those of you keeping track  Wink ), they don't seem to have a long lifetime...(several first generation satellites were launched prior to that, and they're no longer in service). There's 33 of them in orbit right now...not to mention the Air Force's investment in ground stations, building more satellites, etc. etc.

A ground-based system with the same accuracy (well, minus WAAS) for RNAV, which uses high-powered AM transmitters, costs far less. Not to mention, when things first got going (in other words, the receivers appeared on the market), a LORAN receiver was far less costly to manufacture (probably not true today, as there's probably a factory in China turning out mass-produced GPS receivers on a single chip for 30 cents a pop).

LORAN could have been used for time, just as GPS is often used now in the civilian world, too...

In short, I believe LORAN would have been a much better investment in resources than GPS.




Quoting Rwessel (Reply 17):
That is the problem.

My (and a lot of other people's) issue with relying on only GPS is that it's a single system, with a number of vulnerable points, from the limited number of ground stations, to the very low signal strength (jamming, or even faking, the CA signal over a fairly large area is within the reach of anyone with a couple million to spend), and is a system that will require years to rebuild should a catastrophe happen - there is simply no fast way to build satellites and launch vehicles.

Agree 100%.
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PhilSquares
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 3:22 pm



Quoting KELPkid (Reply 18):
In short, I believe LORAN would have been a much better investment in resources than GPS.

But, GPS wasn't developed for the civilian market! The DOD wanted a extremely accurate navigation system that they controlled and development costs were not an issue. The simple fact is the civilian market got a great navigation aid for 0 cost.

The USAF tried using LORAN in the F-4 and it failed miserably. With the need for accurate navigation systems for harden targets the GPS was the best and cheapest way for the military to proceed.
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Soku39
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 4:42 pm



Quoting PhilSquares (Reply 19):
The simple fact is the civilian market got a great navigation aid for 0 cost.

Well there is this whole issue of the taxes we pay...  Wink
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PhilSquares
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 4:51 pm



Quoting Soku39 (Reply 20):
Well there is this whole issue of the taxes we pay...

And your point is? GPS was developed, funded and implemented for the military and it was later opened for the civil market. A high accuracy navigation system was needed and at the end of the day it was going to happen. At least there was a spin off benefit that was allowed to come to the civil market. The elimination of LORAN and NDB is a great step forward. Getting rid of those facilities will save $$$ (read taxpayer $$) in the long run.
Fly fast, live slow
 
KELPkid
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 7:06 pm



Quoting DescendVia (Reply 10):
Off subject but really GPS altitude is not used for navigation unless its WAAS augmented. Raw Baro-GPS altitude is only for RAIM predictions if the required number of satellites are not visible.

Ahh, that explains why the GPS'es at the flight school where I got my instrument always prompted for the current altimeter setting any time you punched a GPS approach in "on-the-fly", I guess it was in case there weren't enough satellites in view for a RAIM calculation  Smile
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DiamondFlyer
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 7:57 pm



Quoting PhilSquares (Reply 21):
The elimination of LORAN and NDB is a great step forward. Getting rid of those facilities will save $$$ (read taxpayer $$) in the long run.

I've got no problems with eliminating the NDB's. LORAN is a needed backup, because, well, if the GPS satellites go down, then we are sunk. Long term, it will be cheaper to keep the LORAN chains up and running, than to shut them down, only to find out in 15 years time that all of the sudden we need them, and have to get it up and running again. With new eLoran, it has just as good as accuracy as GPS does, without augmentation. That's really good, for a radio based system. Hopefully, it doesn't go away any time soon.
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PGNCS
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 8:37 pm



Quoting PhilSquares (Reply 21):
GPS was developed, funded and implemented for the military and it was later opened for the civil market. A high accuracy navigation system was needed and at the end of the day it was going to happen. At least there was a spin off benefit that was allowed to come to the civil market. The elimination of LORAN and NDB is a great step forward. Getting rid of those facilities will save $$$ (read taxpayer $$) in the long run.

Couldn't agree more. This is a tempest in a teapot, and the dollars are far better off allocated to something more needed.

Quoting DiamondFlyer (Reply 23):
I've got no problems with eliminating the NDB's. LORAN is a needed backup, because, well, if the GPS satellites go down, then we are sunk.

We are? I have routinely flown legs of over 10 hours on IRS only nav with great accuracy and no need for any outside navaid. LORAN is an antique whose demise is due.
 
DiamondFlyer
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 9:12 pm



Quoting PGNCS (Reply 24):
We are? I have routinely flown legs of over 10 hours on IRS only nav with great accuracy and no need for any outside navaid. LORAN is an antique whose demise is due.

Really? Great for all the big guys flying 100 million dollar plus airplanes. How about all of us that fly GPS equipped planes. If you elminate VOR's and NDB's, all we have is GPS. That's what the whole NextGen proposal is about. Keep eLORAN around, and give us some backup system.

Another scenario, beyond a solar event knocking out the constellation. Say a massive war breaks out, WWIII. The DOD still maintains control of the GPS system. If they want, I'm sure they can figure out how to degrade the signal to the general public, like SA used to allow for. $30 million is a drop in the bucket. The only real reason this is even being proposed is because the administration knows its one of the few things that people wouldn't complain about.

-DiamondFlyer
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DocLightning
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 9:27 pm



Quoting KELPkid (Reply 9):
There will be a time where keeping 24 satellites + 3 operational spares on orbit will start to weigh us down economically (especially when the said satellites start reaching the end of their operational lifecycles)

To some degree, the system is already obsolete. Because of a need for backwards compatibility, GPS signals can take a long time to acquire and they are very poor at penetrating anything solid. Even a good-sized tree is enough to block a satellite. However, newer GPS systems use some tricks to speed the rate of acquisition and boost accuracy. For example, GPS phones use information from cell towers to localize themselves and figure out which satellite is where and what part of its 60-second transmission cycle it's in. This changes the acquisition time from the 5 or so minutes my Garmin needs to about 15 seconds on my iPhone.

Satellites are very low-maintenance. They don't need power (they have solar panels), they don't rust or suffer from any other effects of weather, they sit in zero-G for their whole lives after deployment without really ever feeling very much inertia...

It'll be a long time before we need to replace the GPS system. And in the scheme of things, it won't be nearly as expensive as building a new airport, but it'll provide a huge benefit.

Quoting DiamondFlyer (Reply 25):
Say a massive war breaks out, WWIII.

If WWIII breaks out, I assure you that civilian use of GPS will be down towards the very bottom of the list of things that worry you.
-Doc Lightning-

"The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars."
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PhilSquares
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 10:06 pm



Quoting DiamondFlyer (Reply 23):
I've got no problems with eliminating the NDB's. LORAN is a needed backup, because, well, if the GPS satellites go down, then we are sunk.

If the GPS systems goes down what guarantees do you have the LORAN won't go down too? Have you tried to fly a NDB approach with a TRW in the vicinity? It's the most useless approach ever developed! There is no reason to ever fly one in today's world. It's an accident waiting to happen!

Quoting DiamondFlyer (Reply 25):
How about all of us that fly GPS equipped planes. If you elminate VOR's and NDB's, all we have is GPS. That's what the whole NextGen proposal is about. Keep eLORAN around, and give us some backup system.

if you have GPS there is no reason not to have RNAV! A RNAV system without GPS will navigate more accurately than any LORAN or NDB system ever could! As PGNCS wrote, long range navigation was around for a long time without any GPS updating and it worked better than LORAN or NDB.
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DiamondFlyer
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RE: New Obama Budget Kills Loran

Fri May 08, 2009 10:13 pm



Quoting PhilSquares (Reply 27):
If the GPS systems goes down what guarantees do you have the LORAN won't go down too? Have you tried to fly a NDB approach with a TRW in the vicinity? It's the most useless approach ever developed! There is no reason to ever fly one in
today's world. It's an accident waiting to happen!

Can't ever say I have. In fact, I've only shot NDB approaches in a simulator, because the flight school I did my instrument at didn't have ADF equipped planes. In respect to LORAN and GPS going down at the same time, I'd safe if that happens, you have bigger problems. One is a space based system, while the other is ground powered. It would take an awfully coordinated attack to take out both systems at the same time.

Quoting PhilSquares (Reply 27):
if you have GPS there is no reason not to have RNAV! A RNAV system without GPS will navigate more accurately than any LORAN or NDB system ever could! As PGNCS wrote, long range navigation was around for a long time without any GPS updating and it worked better than LORAN or NDB.

It comes down to costs. I know RNAV is accurate, but at what costs? And, how are you going to have RNAV without VOR's? I know you could use an INS, but what's the practicality on small aircraft using an INS? In regards to accuracy of LORAN, the new eLORAN has an accuracy design of 20 meters, with reported accuracy of as good as 8 meters. IIRC, that is roughly the same as basic GPS, thus allowing for a LNAV type approach. I think that's quite good for the cost, and it should be kept around

-DiamondFlyer
From my cold, dead hands
 
KELPkid
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RE: New Obama Budget Kills Loran

Sat May 09, 2009 12:58 am



Quoting DocLightning (Reply 26):
To some degree, the system is already obsolete. Because of a need for backwards compatibility, GPS signals can take a long time to acquire .

On a cloudy day, my Garmin Nuvi 200 in my car takes noticably longer to acquire satellites than on a clear day  Smile Ironically, for navigational usage in an aircraft, thick clouds do tend to reflect GPS signals, however not enough to (usually) have much of an effect.

Quoting DocLightning (Reply 26):
and they are very poor at penetrating anything solid.

That has a lot more to do with the fact that you are dealing with microwave band signals than it does with any backwards compatibility issues, that's just the nature of the beast in microwave communications  Smile When I used to work for a broadcast engineer, he would refer to trees as "green attenuators." When a station would lose it's STL (Studio-Transmitter Link, which is microwave), the first thing he would ask the station to do was to check outside and see if any "green attenuators" had grown up into the signal path...  Wink

Quoting DocLightning (Reply 26):
Satellites are very low-maintenance. They don't need power (they have solar panels), they don't rust or suffer from any other effects of weather, they sit in zero-G for their whole lives after deployment without really ever feeling very much inertia...

However, they are exposed to micrometeroids, space junk, and intense solar radiation and heating, and the solar radiation takes it's toll on the solar panels. Imagine a sunburn to the extreme Big grin The solar panels lose a measurable bit of output every year. Not to mention that the materials on board are exposed to several cycles of extreme heating followed by extreme cooling (the sun can heat materials quite warm with no atmosphere to moderate the temperature like it would have down on Earth...). Fortunately for satellites, their orbits are inside the Van Allen Belts (and Earth's magnetic field), which protect them from the solar wind.

Satellite failures can often be sudden-a bird goes off the air, and no one knows (or ever will know) why. Most experts on the matter chalk these sudden failures up to unfortunate encounters with meteoroids or space junk too small to be cataloged by NORAD...
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DescendVia
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RE: New Obama Budget Kills Loran

Sat May 09, 2009 1:08 am



Quoting KELPkid (Reply 22):

Yeah and to tell you the truth I just had read about the baro stuff w/o enough satellites about an hour before I posted..... funny how you put stuff into practice right away. Never had to worry about it since where I'm at you always got at least 8 to 9 in view. Plus now most of the GA planes I rent at have had the WAAS subscription added, so no more need to do RAIM computes anyway.

Quoting DiamondFlyer (Reply 25):
Really? Great for all the big guys flying 100 million dollar plus airplanes. How about all of us that fly GPS equipped planes. If you elminate VOR's and NDB's, all we have is GPS. That's what the whole NextGen proposal is about. Keep eLORAN around, and give us some backup system.

I'm going to admit I have really no idea about eLORAN or for that matter LORAN (other then its theory) but one thing that should be pointed out is this. You say you want to keep a "backup" but the problem is no planes anymore are coming off the line with LORAN stuff equipped. So even though eLORAN is there the little G1000 could care less.
 
DiamondFlyer
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RE: New Obama Budget Kills Loran

Sat May 09, 2009 1:15 am



Quoting DescendVia (Reply 30):
I'm going to admit I have really no idea about eLORAN or for that matter LORAN (other then its theory) but one thing that should be pointed out is this. You say you want to keep a "backup" but the problem is no planes anymore are coming off the line with LORAN stuff equipped. So even though eLORAN is there the little G1000 could care less.

Yes, but it would be possible with the eLORAN chains to install said device, in a short term (matter of weeks to months, if required). Whereas, if the whole GPS constellation goes down, its going to be long term before we have anything near a working constellation. And, honestly, I'd bet that if a large portion of the constellation goes down, it wouldn't be directly replaced, but rather with a newer type system. Either way, its going to be at least 5 years to get that up and running. In the meantime, you could get LORAN up and running in your system, for navigation.

-DiamondFlyer
From my cold, dead hands
 
Soku39
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RE: New Obama Budget Kills Loran

Sat May 09, 2009 1:29 am



Quoting PhilSquares (Reply 21):
And your point is?

That it was not free for the public... as the public finances the military... that's all.
The Ohio Player
 
sccutler
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RE: New Obama Budget Kills Loran

Sat May 09, 2009 3:31 am

The fundamental benefit of keeping Loran? GPS signals are of miniscule power, nad are very easily jammed, whether intentionally or inadvertently.

Loran, on the other hand, is an extremely robust system, stone simple and very effective.

I have a WAAS GPS in my bird, and Garmin GNS430W, but I would not dream of removing my Northstar M1 Loran, which works marvelously well and provides an outstanding backup for a possible loss of GPS signal. It happens.

The net benefit of retaining this simple and fully-built system is obvious; it makes sense.

Hence, its inevitable demise.
...three miles from BRONS, clear for the ILS one five approach...
 
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DocLightning
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RE: New Obama Budget Kills Loran

Sat May 09, 2009 5:56 pm



Quoting KELPkid (Reply 29):

That has a lot more to do with the fact that you are dealing with microwave band signals than it does with any backwards compatibility issues, that's just the nature of the beast in microwave communications

Right. Point is that a better system would not use a band that can't make it through the leaves of a tree.
-Doc Lightning-

"The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars."
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PhilSquares
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RE: New Obama Budget Kills Loran

Sat May 09, 2009 7:15 pm



Quoting DiamondFlyer (Reply 28):
And, how are you going to have RNAV without VOR's?

Easy, did you ever hear of ILS/DME updating? Works great and is just as accurate as LORAN.

Quoting DiamondFlyer (Reply 28):
It comes down to costs. I know RNAV is accurate, but at what costs?

Why not have the user shoulder the cost. Make it mandatory to have a simple IRS system.

Quoting DiamondFlyer (Reply 28):
Can't ever say I have. In fact, I've only shot NDB approaches in a simulator, because the flight school I did my instrument at didn't have ADF equipped planes

So, how can you complain about decommissioning the NDB stations?
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MD11Engineer
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RE: New Obama Budget Kills Loran

Sat May 09, 2009 8:02 pm



Quoting Rwessel (Reply 17):
(jamming, or even faking, the CA signal over a fairly large area is within the reach of anyone with a couple million to spend),

Not millions, a few bucks are enough. A few years ago, when a GPS based road toll system for commercial vehicles was introduced in Germany, some protestors, who feared that the GPS locating system would also come for private vehicles (proposed government keeping track of all vehicle movements in the country), built cheap GPS jammers, which they hid on hilltops. These boxes didn't cost more than appr. $50 to manufacture each and could jam GPS signals (depending on where they were hidden) for up to 50 km.

Jan
Je Suis Charlie et je suis Ahmet aussi
 
DescendVia
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RE: New Obama Budget Kills Loran

Sat May 09, 2009 11:49 pm

Quoting DiamondFlyer (Reply 28):
And, how are you going to have RNAV without VOR's?

Heck the Honeywell IRU models alone are rated at 12 hours with no previous updating in class II RNP10 en route/MNPS airspace. 11.5 hours after the last VOR/DME update and 11.7 hours after the last DME/DME update. So its quite capable.....

Quoting DiamondFlyer (Reply 28):
I've only shot NDB approaches in a simulator



Quoting PhilSquares (Reply 35):
So, how can you complain about decommissioning the NDB stations?

Heck I don't know about other airlines but at UA NDB approaches are not even in the database for Boeing airplanes. They are in the database for the Airbus but the plane cannot shot an NDB approach without it being line selectable since the only authorized way to shot the approach at United is have it manged/manged (I think that is the term since I'm not up much on the Airbus lingo) using APP NAV. That in turn makes only the Bus drives able to short the approach to published minims ( they do have to add 50 to the MDA/HAT if a list of requirements for the runway can't be met) while the Boeing guys need at least 2 miles visibility. Plus the NDB does not even need to be in service. The only NDB approach not authorized in the airbus is a circling only approach since the vertical managed part can't be met.

Sorry if I went a bit off topic but I was just supporting my opinion that all NDBs (even though neat approaches) are a waste of money similar to the current LORAN system for aviation and maybe even in a few years for maritime hence why the phase out should occur.



[Edited 2009-05-09 16:53:12]
 
meister808
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RE: New Obama Budget Kills Loran

Sun May 10, 2009 12:40 am



Quoting DiamondFlyer (Reply 23):
LORAN is a needed backup, because, well, if the GPS satellites go down, then we are sunk.

... we're sunk one way or the other, since the equippage of LORAN is very low...

Quoting DiamondFlyer (Reply 31):
Yes, but it would be possible with the eLORAN chains to install said device, in a short term (matter of weeks to months, if required)

Doubtful, since recieving certification on a new piece of avionics tends to take the better part of a year, after which someone would have to come up with the capital to manufacture these retrofitted LORAN units that work with G1000/Proline/etc. This would take years from start to finish, during which time the same money could have been invested in getting the GPS system back up and running.

Quoting SCCutler (Reply 33):
have a WAAS GPS in my bird, and Garmin GNS430W, but I would not dream of removing my Northstar M1 Loran, which works marvelously well and provides an outstanding backup for a possible loss of GPS signal. It happens.

Well sir, I suppose I do respect greatly your dedication to redundancy, but I think the industry standard VOR also provides an "outstanding backup for a possible loss of GPS signal".

Ditch it, we don't need it.

-Meister
Twin Cessna 812 Victor, Minneapolis Center, we observe your operation in the immediate vicinity of extreme precipitation
 
DiamondFlyer
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RE: New Obama Budget Kills Loran

Sun May 10, 2009 4:40 am



Quoting PhilSquares (Reply 35):
So, how can you complain about decommissioning the NDB stations?

I never once complained about decommissioning NDB stations. If you really want to use that ADF in your plane, use commercial AM broadcast to navigate.

Quoting DescendVia (Reply 37):
Heck the Honeywell IRU models alone are rated at 12 hours with no previous updating in class II RNP10 en route/MNPS airspace. 11.5 hours after the last VOR/DME update and 11.7 hours after the last DME/DME update. So its quite capable.....

What's the price, and more importantly, what's the weight on the unit? I don't doubt that an IRU is capable for navigation, but it's quite overkill for John Doe who wants to do a 200 nm IFR cross country tomorrow, without GPS.

Quoting Meister808 (Reply 38):
Doubtful, since recieving certification on a new piece of avionics tends to take the better part of a year, after which someone would have to come up with the capital to manufacture these retrofitted LORAN units that work with G1000/Proline/etc. This would take years from start to finish, during which time the same money could have been invested in getting the GPS system back up and running.

Fine and dandy, but really, if GPS goes down, you don't need G1000/Proline integration. You need a box that has a CDI on it, to allow for navigation. Unless of course, you can't fly unless the autopilot can't do it for you, in which case you aren't a pilot, but rather nothing more than a systems manager.
If the entire constellation goes down, all you've got left is maybe some LAAS stations. Right now, with today's navigational systems, you don't need LORAN, I realize that. However, if the NextGen system comes to fruition, VOR's are gone, as are the remaining NDB's. That leaves nothing but Sat-Nav. LORAN is a cheap, accurate, effective and easy to use backup to that system.

-DiamondFlyer
From my cold, dead hands
 
rwessel
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RE: New Obama Budget Kills Loran

Mon May 11, 2009 11:14 pm



Quoting MD11Engineer (Reply 36):
Not millions, a few bucks are enough. A few years ago, when a GPS based road toll system for commercial vehicles was introduced in Germany, some protestors, who feared that the GPS locating system would also come for private vehicles (proposed government keeping track of all vehicle movements in the country), built cheap GPS jammers, which they hid on hilltops. These boxes didn't cost more than appr. $50 to manufacture each and could jam GPS signals (depending on where they were hidden) for up to 50 km.

True - straight jamming is trivial. My (unclearly written) cost estimate applied to producing a fake set of GPS signals.
 
sccutler
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RE: New Obama Budget Kills Loran

Sat May 16, 2009 6:05 am



Quoting Meister808 (Reply 38):
Quoting SCCutler (Reply 33):
have a WAAS GPS in my bird, and Garmin GNS430W, but I would not dream of removing my Northstar M1 Loran, which works marvelously well and provides an outstanding backup for a possible loss of GPS signal. It happens.

Well sir, I suppose I do respect greatly your dedication to redundancy, but I think the industry standard VOR also provides an "outstanding backup for a possible loss of GPS signal".

Ditch it, we don't need it.

Understood, but the cost of maintaining the vast network of VOR stations virtually guarantees that they will be eliminated. Maintaining the relatively few ground facilities required for LORAN is modest in cost, by comparison.
...three miles from BRONS, clear for the ILS one five approach...
 
L-188
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RE: New Obama Budget Kills Loran

Mon May 18, 2009 3:50 am



Quoting DiamondFlyer (Reply 39):
I never once complained about decommissioning NDB stations. If you really want to use that ADF in your plane, use commercial AM broadcast to navigate.

True, but I don't think I really want to trust my life to an "Air America" broadcast.  scared 

But the fact that ADF isn't reliant on USGovt facilities is probably one of it's greatest features.

There are active LORAN stations in Alaska, Tok, Saint Paul and Attu. Frankly I think it would be a shame for young Coastguardsmen to miss out at at chance for a year at Loran Station Attu.

Loran has always been more important to navigation in ships then it has been for aircraft. But to retire a mature reliable system in my mind is not work the cost savings.

But it isn't the first time, a lot of people complained about the loss of the 4 course radio range also.

GPS at times isn't all it is cracked up to be, as mentioned it can be interfered with, there are parts of this world where you can't get the required number of satillites (north side of Alaska Brooks range for example).

As my grandfather used to say, "Despite technology we still use shovels to dig graves". They still make Sextants also.
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
KELPkid
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RE: New Obama Budget Kills Loran

Mon May 18, 2009 5:53 am



Quoting L-188 (Reply 42):
As my grandfather used to say, "Despite technology we still use shovels to dig graves". They still make Sextants also.

I have one of those, and I taught my self to use it (okay, so that I could teach a bunch of 3rd-5th grade kids a little bit about nautical navigation...). Gotta say, Oregon is about the worst place to use it, too...the cloud cover here gets in the way  Smile I have never tried to use it in the air, nor do I think I ever would...
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
L-188
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RE: New Obama Budget Kills Loran

Mon May 18, 2009 6:45 am

Omega
RNAV
MLS
Radio Ranges

A lot of systems have died over the years.

Actually when it comes to naviation I am surprised that Inertial Navigation hasn't been translated into smaller more affordable units. It has been around for 50 years now and really hasn't been downsized or become any cheaper.
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
DescendVia
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RE: New Obama Budget Kills Loran

Mon May 18, 2009 2:20 pm



Quoting L-188 (Reply 44):
RNAV

Not so much....... that is pretty much the basis for this topic  Wink
 
KELPkid
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RE: New Obama Budget Kills Loran

Mon May 18, 2009 2:56 pm



Quoting DescendVia (Reply 45):

Quoting L-188 (Reply 44):
RNAV

Not so much....... that is pretty much the basis for this topic

Traditionally, RNAV was based upon analog computations of nearby VOR's, localizers, and their respective DME readings  Wink If you bought an RNAV unit in the late 1970's or early 1980's, this was how it worked.
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
L-188
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RE: New Obama Budget Kills Loran

Tue May 19, 2009 3:06 am



Quoting KELPkid (Reply 46):
Quoting DescendVia (Reply 45):

Quoting L-188 (Reply 44):
RNAV

Not so much....... that is pretty much the basis for this topic

Traditionally, RNAV was based upon analog computations of nearby VOR's, localizers, and their respective DME readings If you bought an RNAV unit in the late 1970's or early 1980's, this was how it worked.

RNAV is going to have a really hard time if they shut down all the VOR's which has been proposed more then once.

And I am going to get some flack for this, but it really is a dead system thanks to GPS direct.
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
DescendVia
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RE: New Obama Budget Kills Loran

Tue May 19, 2009 3:41 am



Quoting KELPkid (Reply 46):
Traditionally, RNAV was based upon analog computations of nearby VOR's, localizers, and their respective DME readings Wink If you bought an RNAV unit in the late 1970's or early 1980's, this was how it worked.

Exactly but I'm more referring to the term RNAV in its current form........  Smile
 
rwessel
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RE: New Obama Budget Kills Loran

Thu May 21, 2009 5:59 am

Just to stir the pot a bit:

http://www.newscientist.com/article/...atellites-to-hit-gps-accuracy.html

"Ageing satellites to hit GPS accuracy"

Summary and additional commentary:

GPS works best when at least four starlets are visible to the receiver. This requires 24 active birds. If there are fewer, there will be times when only three birds are visible (assuming, of course that it’s not a lot less than 24), which will result in a significant reduction in possible accuracy.

There are currently 31* birds in orbit (the extras are spares, and are now mostly older satellites that are still operational), including Block IIs, IIAs, and IIRs, but with the current delay in launching the Block IIF** birds (three years behind schedule - the first is now planned to launch in November), *13* are more than four years past their design lifetime (which varies based on which model, but the IIs and IIAs had a design life of 7.5 years, the IIRs 10 years). The Block II birds were launched in 1989 and 1990, and seven of them are still on the active list, the youngest now being a bit more than 11 years past its 7.5 year design lifespan.

The GAO estimates that there’s a 20% chance that the number of active birds will fall below 24 one or more times in 2010 and 2011. Note that it’s not just the chance of losing 7 birds, the GPS satellites are in six different orbital planes, and each plane is supposed to have a spare. Moving a spare between planes will be time consuming at best, and will certainly require a great deal of fuel (which probably rules out moving any of the older birds).

They further mention that if the next generation (block IIIA) birds fall only two years behind schedule, that by the GAO's estimate, there's a 90% chance that the number of working birds will fall below 24 in 2018.


*My other source says 29, but I think the two extra birds are inactive spares

**Why the IIFs come after the IIRs, I have no idea…

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