Fed.gov prepares back up for GPS

[Balog]

Apparently DHS is revamping the old LORAN system in case of a failure of GPS. Interesting but short article from Popular Mechanics.

http://www.popularmechanics.com/technology/industry/4266972.html

[Manedwolf]

I have an Army Air Corps navigator's sextant in its box...

[Ben]

I'm actually not sure what the point of this would be if it's targeted at economic, civilian uses of nav-aids. It would require trucking companies, FEDEX, Joe Users, etc. to purchase LORAN receivers for "just in case". Who's going to fork over bucks for that as a backup system? Besides the already working coastal LORAN, ships can always fall as far back as Manedwolf's sextant if they have to, and aircraft can use the TACANs, which anybody with a radio is already equipped for.

Am I missing something?

[Tallpine]

More of your tax dollars at waste

[never_retreat]

Yes but when you start to combine gps and loran signals you get even more accurate positioning.
FYI the coast guard maintains the loran system, unfortunately the coast guard is part of the joke they call homeland security now. 

[MicroBalrog]

Would it be legal for a private company to start it's own positioning sat business?

Also, has anyone tried GLONASS?

[Ben]

Yes but when you start to combine gps and loran signals you get even more accurate positioning.

But this is based on GPS going down, so they wouldn't be simultaneously active. Besides, in civilian transportation and business, I can't think of any reason for better than plus or minus 5 meters.

[Silver Bullet]

Maybe it's for military uses if the Chinese shoot down our satellites ?

I don't know how LORAN works.

[Manedwolf]

How about just saving money by not phasing out VOR and DME as they seem to have planned to?

[Warhorse]

LORAN is a HF (High Frequency) signal that is based on calculation of time difference of arrival from three widely spaced land-based transmitters that are synchronized in time, basically the same principal upon which GPS is based. These are set up in a series of "chains" of related stations, each operating on its own grid. As you move to different geographic areas, you have to switch to a different grid to maintain accuracy and, perhaps, even receive a full set of signals. Modern LORAN receivers will do this automatically, making operation as easy as with GPS. The LORAN system was not anywhere near as accurate as GPS, even when "selective availability" on GPS was active. (Deliberate degradation of GPS accuracy to civilian use.)

The upgrade to LORAN will provide enhanced accuracy and that system is less easily knocked out than GPS. Reasons are stated in the referenced article.

Why do this? It is a sensible backup for military use, as well as civilian aircraft and vessels. I am a sailor and do both offshore and coastal cruising. I am very pleased to hear that LORAN will continue, as I have personally experienced times when GPS became unavailable for some unknown reason. If you are in a thick fog (as I have often experienced, especially in DownEast waters), electronic navigation capability can really help keep your underwear unsoiled at times.

Having LORAN available to the civilian marker is somewhat akin to the reason that you have a fire extinguisher in your home. It is comforting even if you never use it. But if you  do need it........


Warhorse

[RevDisk]

Redundant backups are a good thing.

Plus, theoretically, combining multiple systems can increase accuracy. 

Folks are already working on integrated devics that read GLONASS (incomplete as of 2008), Galileo, COMPASS, and IRNSS/GAGAN.  Most commercial US GPS devices already do the same thing, with Wide Area Augmentation System (WAAS).  Ground stations that provide extra data for increased accuracy.

[Gewehr98]

Redundancy is good.

I had dual GPS, all the radio nav-aids, INS, and a sextant for cell shots.  I'm almost embarrased to say I know how to use Manedwolf's sextant, but he'll have to cut a hole for the sextant's periscope in the roof of his riceburner to get a clear shot of the sun or moon.  It was our backup in the event we lost GPS or our INS gyros started tumbling, especially when orbiting around 90 North for extended periods of time.  Othewise, our INS was the main reference, but our navigators had to be fluent in all means of fixing their position, including dead reckoning, and were evaluated every 18 months or sooner on their skills. 

Celestial navigation is a dying art, and GPS hastened its demise. 

[Manedwolf]

Nothing wrong with knowing how to use it. I have the barest skill with it from reading online copies of the training manuals.

I'd found it in mint condition at a flea market, smelling like it'd been sealed forever, and it still works just fine.

As for cars, that's what sunroofs are for. If someone else is driving. Otherwise, sighting tends to lead to a loud and expensive noise.

[Tallpine]

It scares me to think people can't find their way around on dry land without GPS 

On water, of course - that is another thing.

[Ben]

Redundant backups are a good thing.

Fellers, I'm not arguing that redundancy isn't a good thing -- I like knowing that if my GPS goes out when I fly I can switch to radio navigation (or even the compass, since when I was learning, that was the only nav instrument that worked half the time in the trainer  ). But unless I'm misinterpreting it, this (from the article at least) seems to focus on civilian uses for LORAN, and outside the maritime community, I just don't see everyone who uses GPS going out and buying a LORAN receiver to put in their semis, delivery vans, or even fire trucks and police cars to be used only if GPS goes down.

Defense is a different issue, but again, I'm not seeing that that's the focus here.

[Warhorse]

BenW

While the "publicity" seems to be emphasizing civilian use, don't kid yourself. It's the military that is driving all this, just as they did the original GPS project. Who do you think is footing the bill? (That is, other than the ultimate payer, John Q. Public.) Civilian spillover of use is really a side benefit and a significant benefit it is when all uses are considered.

Lest I be misunderstood, I am all in favor of this. Any system that I ever designed or built always had some sort of backup to provide for "graceful degradation" of its operation when Murphy reared his head.

Warhorse

[Manedwolf]

I suspect the "civilian" side they mean is not ground vehicles. I think they're talking about keeping airliners from having to have a ground stop if they get so dependent on GPS that other means of navigation fall out of use, and something happens to GPS. It can be jammed, everyone knows the Russians made GPS jammers.

[Matthew Carberry]

I suspect the "civilian" side they mean is not ground vehicles. I think they're talking about keeping airliners from having to have a ground stop if they get so dependent on GPS that other means of navigation fall out of use, and something happens to GPS. It can be jammed, everyone knows the Russians made GPS jammers.

Point of order.

I did in fact not know that, so you were wrong.   

But since that has been corrected, we can move on with our generalizations. 


(I did actually know that, but couldn't/wouldn't pass up the "joke")

[Manedwolf]

I suspect the "civilian" side they mean is not ground vehicles. I think they're talking about keeping airliners from having to have a ground stop if they get so dependent on GPS that other means of navigation fall out of use, and something happens to GPS. It can be jammed, everyone knows the Russians made GPS jammers.

Point of order.

I did in fact not know that, so you were wrong.   

But since that has been corrected, we can move on with our generalizations. 


(I did actually know that, but couldn't/wouldn't pass up the "joke")

Hee. Well, I should have said "Everyone in the intelligence community". In the general population, only those interested in such things. The fact that such jammers have been purchased on the black market and open market overseas has probably alarmed some people in strategic offices who saw all the eggs moving towards the GPS basket when it comes to civilian air transportation. The circuitry is easy to duplicate, anyone could get a shop in China to crank out the boards without even knowing what they're for, and then deploy jammers all over. They could be found pretty easily with a directional antenna, just like stuck-mic radios at an airport, but if there were a lot of them, that could be Bad.

[RevDisk]

Hee. Well, I should have said "Everyone in the intelligence community". In the general population, only those interested in such things. The fact that such jammers have been purchased on the black market and open market overseas has probably alarmed some people in strategic offices who saw all the eggs moving towards the GPS basket when it comes to civilian air transportation. The circuitry is easy to duplicate, anyone could get a shop in China to crank out the boards without even knowing what they're for, and then deploy jammers all over. They could be found pretty easily with a directional antenna, just like stuck-mic radios at an airport, but if there were a lot of them, that could be Bad.

Yea, the smarter folks are trying to move away from giant jammers.  Previously, it was a really good way to get anti-radiation guided missile through the antenna.   

Now, enterprising car thieves have combo GPS/GSM jammers for stealing cars with more sophisticated recovery systems.  Handily plugs straight into the cigarette lighter jack, or battery power.

[Manedwolf]

Hee. Well, I should have said "Everyone in the intelligence community". In the general population, only those interested in such things. The fact that such jammers have been purchased on the black market and open market overseas has probably alarmed some people in strategic offices who saw all the eggs moving towards the GPS basket when it comes to civilian air transportation. The circuitry is easy to duplicate, anyone could get a shop in China to crank out the boards without even knowing what they're for, and then deploy jammers all over. They could be found pretty easily with a directional antenna, just like stuck-mic radios at an airport, but if there were a lot of them, that could be Bad.

Yea, the smarter folks are trying to move away from giant jammers.  Previously, it was a really good way to get anti-radiation guided missile through the antenna.   

Now, enterprising car thieves have combo GPS/GSM jammers for stealing cars with more sophisticated recovery systems.  Handily plugs straight into the cigarette lighter jack, or battery power.

Heard about those. I suspect they're more used in places like Miami, where a stolen supercar or $80+K luxury car can be in a cargo box and on its way to South America in under half an hour.

[RevDisk]

Heard about those. I suspect they're more used in places like Miami, where a stolen supercar or $80+K luxury car can be in a cargo box and on its way to South America in under half an hour.

Maimi, NYC, LA.  Come to think of it, anywhere with a significant ComBloc immigrant population.  Mainly Russian or Ukrainian.  Hrm.

[MechAg94]

I seem to remember the military bragging that they knocked out an Iraqi GPS jammer with a GPS guided bomb.  I guess that one didn't work too well. 

[MechAg94]

Locally, I have a county by county map of Texas with all the backroads.  With that and a compass, I think I could make my way around if I needed to.  I guess I am behind the times since I don't have a GPS. 

[Tallpine]

Yeah, it's pretty hard to "jam" the dead tree on the hill and the rock that looks like a sleeping elk.