SailNet Community banner

1 - 17 of 17 Posts

·
Larus Marinus
Joined
·
1,756 Posts
Discussion Starter #1
So the DHS has decided to spend some more $s.

<st1:date year="2008" day="7" month="2">February 7, 2008</st1:date><o></o>
Contact: (202) 282-8010<o></o>
<o></o>
STATEMENT FROM DHS PRESS SECRETARY LAURA KEEHHNER ON THE ADOPTION OF NATIONAL BACKUP SYSTEM TO GPS<o></o>
<o></o>
Today the U.S. Department of Homeland Security will begin implementing an independent national positioning, navigation and timing system that complements the Global Positioning System (GPS) in the event of an outage or disruption in service. <o></o>
<o></o>
The enhanced Loran, or eLoran, system will be a land-based, independent system and will mitigate any safety, security, or economic effects of a GPS outage or disruption. GPS is a satellite-based system widely used for positioning, navigation, and timing. The eLoran system will be an enhanced and modernized version of Loran-C, long used by mariners and aviators and originally developed for civil marine use in coastal areas.
<o></o>
In addition to providing backup coverage, the signal strength and penetration capability of eLoran will provide support to first responders and other operators in environments that GPS cannot support, such as under heavy foliage, in some underground areas, and in dense high-rise structures. The system will use modernized transmitting stations and an upgraded network. <o></o>
 

·
Banned
Joined
·
711 Posts
I would think any Loran C will still function, but a newer eLoran unit will probably offer enhanced features. Just speculation at this point.
Anyway, YaaHooo!!!!! I for one, am pickled tink!
 

·
Owner, Green Bay Packers
Joined
·
10,318 Posts
I'd be highly curious as to DoD's thoughts on the matter. It was just a short time ago that all the talk was of the elimination of Loran C. Does DoD think there is a need, and what types of interruptions to GPS are we considering?

I'm not at all sure that a security threat to GPS satellites is a viable possibility within the next ten to twenty years. I can think of quite a number of security threats that don't involve GPS satellites that are of a more pressing nature.

But then the mind does wander and cogitate on these things a bit as things are not always as they seem. What if the need for a back-up system was because of an intentional shut-down of the GPS system? Let's face it. Your basic $100 GPS unit has all the requirements to guide a ballistic missle, even without the full Camaraderie Lost Bays of Tortuga Chartplotter upgrade. your local West Marine is selling a precision guidance system the bomber pilots of WWII would have salivated over. What it actually guides is limited only by the resources of the nefarious end users.

For instance. The technology is already present for the control of an unmanned super tanker which could certainly sail into and detonate in lower NY Harbor. A simple matter of piracy, half a day's work, all conducted in the southern ocean would yield a tremendous bomb deliverable thrity days hence to NYC. Detonated under the Verrazano Narrows Bridge, it might close the entire port of NY/NJ indefinitely. The numbers killed could be mind-boggling. Obviously the mind also contemplates nascent missile technology as well.

The "what-if" planners at DHS and DoD have probably considered the need to shut down GPS intentionally. At the same time they are probably aware of the lack of other viable radio navigation systems. I'm quite sure they're only vaguely aware of Camaraderie's proficiency at celestial navigation.

What's wrong with this theory?
 

·
Registered
Joined
·
2,527 Posts
Sway,

What is wrong with this theory is the assumption Camaraderie is proficient at celestial navigation.:D :D :D :D

Don't use the red button Cam.:rolleyes: :rolleyes:
 

·
Larus Marinus
Joined
·
1,756 Posts
Discussion Starter #11
I think the eLORAN philosophy (simplified) says:-

GPS - weak signal - bad
LORAN - big pulses - good
eLORAN - fixes some of LORAN C's little problems.

For nice places in the world:-
When bad guys attack, deny GPS locally with jamming (they do or we do?)
Goodies use eLORAN (bad guys don't know how?).

For not so nice places in the world.
When attacking bad guys, deny GPS locally with jamming (they do or we do?)
eLORAN is not available as it is not supported by bad guys' countries.

For sad places in the world.
GPS is bound to be (un)intentionally denied (sometime, occasionally, please).
DME will not work, radar will not work, pilotage will not work, navigators have lost their trade, ....
eLORAN will be there to save the day (please invest heavily).

P.S. You can navigate in your fallout shelter with eLORAN. It's definitely better than GPS for that.
 

·
blue collar cruiser
Joined
·
370 Posts
Last months Soundings magazine (Feb. 08), which doesn't seem to be on their website in full yet, has an article about the disruption of GPS as a result of solar flares. Basically solar flares inject high energy electrons in the atmosphere and produce broad frequency radio waves that create noise over those frequencies including those used by GPS, says Cornell U., BU, MIT and NOAA. They recorded a flare in Dec. 06 which disrupted GPS signals on the lighted side of Earth, some places suffered loss of signal strength or accuracy-others lost the signal entirely, for 10 minutes. They expect it to get worse over the next few years.
 

·
moderate?
Joined
·
13,875 Posts
SS...the article you cite is essentially correct and events should increase as the solar cycle increases over the next few years but here is a bit more scoop. Does not seem to be anything sailors need be concerned about unless they rely on chartplotters and no paper.

"The radio bursts don’t actually damage equipment but only interfere with transmissions between GPS satellites and receivers. Some GPS equipment may be affected for about 30 minutes, Kintner said, “but that’s really an upper limit.” This means that the risks are greater for some GPS users than for others.

“This past event, (Dec 06), was sort of two really intense pulses that lasted three to four minutes each, so this is not a major outage if you’re driving a car or hiking,” Kintner said. “It’s really a concern for people who want uninterrupted operation.”
http://www.gcn.com/print/26_08/43512-1.html
 

·
Owner, Green Bay Packers
Joined
·
10,318 Posts
Solar flares also disrupt Loran sporadically.

I'll persist in thinking that this has something to do with more than a ten minute or even a half day shut-down of GPS, to justify the on-going expense. I'd expect we'll hear more about it sooner than later.
 

·
Larus Marinus
Joined
·
1,756 Posts
Discussion Starter #15 (Edited)
Maybe the "e" in the DHS version of eLORAN stands for encrypted..... ??

Just found this:-

Homeland Security plans to modernize Coast Guard navigation system

By Bob Brewin [email protected] February 12, 2008

The Homeland Security Department plans to modernize and upgrade the Coast Guard's terrestrial Long Range Navigation (LORAN) system to serve as backup to the satellite-based Global Positioning System, which is used for navigation to determine location and precise timing information. The decision ended a cliffhanger policy-making process that started in January 2007, when DHS and the Transportation Department asked for public comment on whether to shut down LORAN or upgrade it.

On Feb. 7, DHS spokeswoman Laura Keehner said the department decided to use an enhanced version, eLORAN, to provide backup to GPS. The system will "mitigate any safety, security or economic effects of a GPS outage or disruption," she said. The Transportation Department's Volpe National Transportation Systems Center urged development of an alternative to GPS in a 2001 report which concluded the satellite-based system could be knocked out by jamming its high-frequency, low-power signals. The report suggested LORAN as a backup. Keehner added that LORAN has the capability GPS lacks in urban canyons as well as in heavy foliage to provide precise location and navigation information to first responders working in such areas.

The Coast Guard operates 24 LORAN stations nationwide to help users, including ships and planes, determine their location. Nineteen have been upgraded to eLORAN, which broadcasts a data channel to improve accuracy, signal availability and integrity of information. The International LORAN Association says the modernization boosts position accuracy to between 8 feet and 65 feet, with availability measured at 99.9 percent and integrity at 99.99 percent.
The DHS decision marks a "tremendous step forward" for eLORAN and a long-needed GPS backup, said Zachariah Conover, president and chief executive officer of Maine-based CrossRate
Technology, which has developed integrated GPS/LORAN receivers for maritime users. Priced from $1,000 to $1,500, the equipment will go on sale in April, he said.
Despite Homeland Security's endorsement, eLORAN funding remains a problem, Conover said. The proposed fiscal 2009 budget (page 98) for eLORAN is $34.5 million. Conover estimated it will
take $45 million to operate the system. DHS said in its budget (page 501) that the system would be transferred from the Coast Guard to the National Communications System (page 513), which will oversee LORAN modernization.

On Oct. 5, 2007, Coast Guard Capt. Curtis Dubay told the National Position Navigation and Timing Advisory Board that modernization of LORAN system would cost $400 million plus another $50 million for expansion. Conover said the Coast Guard estimate is high and that the work could be done for about $120 million.
Mike Harrison, a consultant with Aviation Management Associates in Alexandria, Va., who wrote a white paper on GPS backup for the Federal Aviation Administration in 2006, said the eLORAN system could come in at less than a third of the cost to operate and maintain existing FAA ground navigation equipment. Such systems include the VHF Omni-Directional Radio Range (VOR) beacon that pilots use to get their bearings as they navigate cross country.
Harrison expected business aircraft and the 400,000 private pilots flying within the United States to embrace eLORAN. But commercial airlines, he said, will stick with GPS and another
ground-based system, Distance Measuring Equipment, because LORAN and eLORAN systems do not have worldwide coverage.

CrossRate's Conover said eLORAN, which transmits high-power, low-frequency signals, can work much better in urban environments than GPS, which transmits high-frequency, low-power
signals, and should be a boon to both first responders and truck fleet operators. Urban canyons can cause GPS outages as high as 80 percent of the time because receivers have a hard time picking up satellite signals, he said.

eLORAN also will provide a reliable backup for timing signals essential to the operation of all types of telecommunications networks, including cellular systems, Conover said.
The eLORAN signals are so strong, network operators will be able to pick up timing data without installing an external antenna.
 

·
Registered
Joined
·
1,889 Posts
From a technical perspective, eLoran which utilizes low frequencies and extremely powerful land-based transmitters is highly unlikely to be disturbed by the same kinds of things which can knock out GPS systems (principally, solar flares and jamming).

The "e" stands for "enhanced". The enhanced component is the addition of a "data channel" which helps to improve accuracy...very useful for critical systems like landing aircraft and ships entering harbors might need.

The availability figures for loran are astonishingly high: 99.99%.

One place to read about eLoran is on the USCG website: http://www.navcen.uscg.gov/eloran/overview.htm

I carry two legacy lorans aboard...a Furuno LC-90MKII and a Micrologic Voyager. They can be seen here, next to the legacy Brookes and Gatehouse RDF system: http://gallery.wdsg.com/Misc-Stuff-SBF/NavStn_0143?full=1

This is in addition to two fixed and three portable GPS devices, and an assortment of other nav gear.

Overkill? Yeah, for sure. But it leaves me absolutely NO EXCUSE for not knowing exactly where I am at all times :)

Bill

Here's a more detailed explanation of eLoran (from the International Loran Association):

Quote
The eLoran System

eLoran meets a set of worldwide standards and operates wholly independently of GPS, GLONASS, Galileo, or any future GNSS. Each user’s eLoran receiver will be operable in all regions where an eLoran service is provided. eLoran receivers shall work automatically, with minimal user input.
The core eLoran system comprises modernized control centers, transmitting stations and monitoring sites. eLoran transmissions are synchronized to an identifiable, publicly-certified, source of Coordinated Universal Time (UTC) by a method wholly independent of GNSS. This allows the eLoran Service Provider to operate on a time scale that is synchronized with but operates independently of GNSS time scales. Synchronizing to a common time source will also allow receivers to employ a mixture of eLoran and satellite signals.

The principal difference between eLoran and traditional Loran-C is the addition of a data channel on the transmitted signal. This conveys application-specific corrections, warnings, and signal integrity information to the user’s receiver. It is this data channel that allows eLoran to meet the very demanding requirements of landing aircraft using non-precision instrument approaches and bringing ships safely into harbor in low-visibility conditions. eLoran is also capable of providing the exceedingly precise time and frequency references needed by the telecommunications systems that carry voice and internet communications. Unquote

This knowing exactly where you are at all times is great, but it doesn't necessarily help you know where you're going or why :)

B.
 

·
Registered
Joined
·
3,070 Posts
Okay! Now the question is; When are the loran receivers becoming available again in the marine market place. Will they be separate or combine with gps units (two antennas required?) Compatible with AIS, the Radar, and your computer?
Good thing I have a sextant and know how to use it.
 
1 - 17 of 17 Posts
Top