There is a chance that e-loran may be a reality in the USA

T

thataway

Active member
Panbo today: http://www.panbo.com/archives/2014/02/e ... ng-un.html

This is Thanks to Kim Jong Un, in North Korea who has been successful in jamming the GPS signals in the S China Sea, and South Korean Peninsula.

The reality of loss of GPS signals, has brought around the reality that we need a redundant navigation system. Korea is going ahead with e-loran in 2014. e Loran is a reality in part of Europe.

Unfortunately the US has deactivated all Loran C stations--and destroyed at least 2 of the towers.

It is interesting if you have the time to listen to the congressional committee and the response from the Coast Guard, NOAA, Corp of Engineers, about the various aids to Navigation.
http://transportation.house.gov/calenda ... tID=366184

The emphasis of the congressional hearing is "e navigation" and this in itself examines the use of AIS, the use of smart phones, internet, free charts, weather etc, all in one combined navigational service and interphase.
 
ssobol":187ut9kt said:
What's to stop them from jamming the Loran (or e-Loran) signals too?
Click to expand...

e Loran uses a very high power terrestrial based signal. GPS is a very low power narrow frequency band, satellite based system. The GPS is far easier to jam, because of its low power. Could e Loran be jammed--certainly any radio signal can be jammed, but there are a number of reasons this would be difficult--and require a lot of power.

What is amazing is how often the GPS signal is jammed: for example at the London stock exchange there are 10 to 20 minutes a day the GPS signal is jammed (GPS is used for precise timing in the Stock exchanges). This is caused by trucks (mostly) where the employee driving the truck carries a $75 jammer he bought on the internet, to jam the GPS tracker in his truck. The same is true at many of our air ports. You can buy for about $3,000 a GPS jammer the size of a suitcase which is good for up to several miles. Now, some of our military, and munitions have "jam proof"--technology--but remember our military uses a better level of GPS than is available for commercial or recreational use.

Secondary, we know that China has the technology to take out our GPS satellites--Many militaries realize that major wars will not have the luxury of GPS. England, most of Euro;pe and the Middle East realize that and are strengthing their e-loran (and some still have Loran C). What is amazing is that the private estimate to implement E loran in the US is only 40 million dollars. One of the hang ups is the Dept of Homehand security, who now controls the remaining Loran C towers. In some ways it is cheaper to use these towers and build chains of Loran e , than it is to demolish the towers and dispose of the land and related facilities. A real paradox.

Also mentioned were Lighthouse fees. Most likely few of the C Brats have ever paid these. As we were cruising to over 40 other countries, often we were assessed a Lighthouse fee as part of clearing into the country. That is what they use to maintain their Aids to Navigation--DECCA, e-Loran etc...

The above hearing is most interesting. I have now listened to its entirety. Rep. Duncan Hunter is a most engaging chair of this subcommittee. There are two segments, the latter is civilian--Academic, a retired Coast Guard officer, Dana A. Goward, who is proponent for e-loran with his Director, Marine Transportation Systems; Captain Lynn Korwatch, Executive Director, Marine Exchange of the San Francisco Bay Region.

There is a contrast between the first panel, which includes a CG admiral, an exec of the Corp of Engineers and a ranking official of NOAA, with the slowness of government, and the political system contrasted with the rapid advance of the private system of enterprise. For example there was no plea for more funds for the Corp to dredge the ICW, even though in places it is almost impassable, but for anything larger than a c Dory!
 
I guess I better dig out my old compass! Now where is it? I know its around here somewhere! And there was something else---what were they called?
Oh yeah charts made of paper. Those were the good old days. Now I just have to remember how to use those things again!
 
Bob-

Does the e Loran use the same antennas as the Loran C?

I assume one needs a whole new receiver, of course, to process the signals.

Joe. :teeth :thup
 
Joe,
Most likely one would not use the same antenna as we used for Loran C. Although the frequency of Loran C (90 to 110 kHz) is included in the eLoran spectrum (100kHz), the antenna seems to be different. Although both use timed impulse, the technology is different, and more precise. (at least 10 meter accuracy)

There is an e field antenna and a h field loop antenna--the characteristics of each is different.

Photo of h field loop antenna:
390_CrossRate_Receiver_Harbor.jpg


Photo of e field antenna:
E-Field-Antennas.png
(some were taller and more cylindrical--see the link below:)

From Research and Navigation web site:

eLoran is a low frequency terrestrial navigation system based on a number of transmission stations, which emit precisely timed and shaped radio pulses centred at 100 kHz radio frequency. Each station emits a sequence of 8 pulses spaced 1000 microseconds apart. The stations are grouped into chains, which each consists of a single master station and two or more secondary stations. The master station transmits first, followed by successive transmissions from each of the secondary stations of the chain. The master/secondary transmission sequence is repeated periodically, with the period between repetitions called the Group Repetition Interval (GRI).
eLoran represents a move away from the hyperbolic Loran-C of old. Today, modern receivers can measure the "time of arrival" of signals from many stations (and from multiple chains) at once. eLoran is derived from the Loran-C system, but uses solid-state transmitters, precise timing (using atomic clocks) and a data channel to provide correction and integrity messages. The use of built-in microprocessors means that the receiver is also able to output latitude and longitude directly. Modern eLoran works in much the same way as GPS but it is an independent and complementary system, offering a navigation system with no failure modes in common with GPS or any other satellite based system.
Click to expand...



Here ia a technical, but good presentation about one of the systems currently in use:
http://www.ursanav.com/sites/default/fi ... torial.pdf
 
OK, GPS is going to be in trouble and we ought to have a backup. Well, instead of us recreational boaters, someone ought to get the word out to the airlines and the FAA (USA) and SESAR (Europe.)

I was reading the AIAA journal, Aerospace America, and they're discussing both present and future air traffic control systems. Right now, Boeing is developing GBAS, an automated GPS augmented landing system. This is under test at New York and New Jersey airports as we type. Next, the FAA and SESAR is jointly developing automated air traffic control technology. They're speaking of keeping an airplane within 10 sec of its assigned flight path. And, yes GPS is in the mix. Thats by 2020.

So, if a trucker with his $35 GPs eliminator can disrupt GPS signals and North Korea can shut down those signals in South Korea, the airlines aren't aware of those impacts. In fact, they're making their airplanes (and us, when we fly,) more dependent on GPS.

So, either GPS will be made more jam resistant, or we'll see some interesting problems. But, as of now, GPS is in our future, not eLoran.

Comments?

Boris
 
Boris,
The FAA, FCC, Honeywell (the builders of the SLS-4000 SmartPath® Landing System), the Military, many other governments (including Iran), are very aware of the problems with both jamming and spoofing GPS. The augmented landing system, is localized to each air port, and similar in many way to the differential precision GPS, have been made more resistant to jamming--but it still occurs about 5 times a day at Newark. Several have been caught--but it took almost two years to catch one of these jammers (who was fined $32,000 and lost his job).

According to the FCC GBAS is used at Newark Liberty International Airport (EWR) and Houston George Bush Intercontinental Airport (IAH). Internationally, Bremen Airport (BRE) in Germany. Certainly Boeing has been a major developer, but GBAS equipage is standard on Boeing 747-8 and Boeing 787 aircraft. GBAS is an option on Boeing 737-Next Generation (737-600/-700/-800/-900), Airbus A320, A330/340, and A380 aircraft.

There is no question that the world now runs on GPS--our cars, (and we are looking at automatic driving cars in the near future). All sorts of timing devices, etc. civil aviation is now using GPS, port security uses GPS, with AIS, and other computer interphases.

The question is it worth $45 million (Vs the many billions spent on GPS) for an alternate system which can be used by many of these current users of GPS? I suspect that the answer is yes. e Loran does not have the precision for air traffic, (But the GBAS program has been in the works for over 25 years). There are many other functions beside location which are involved with the GPS system, which can be answered by e Loran. There exists the possibility for local area augmentation for eLoran, just as there is for GPS--but using the long wave frequencies--which are far more difficult to jam. (basically this was what was being done when we were using the old RDF frequencies for DGPS before SA was switched off.
 
Bob, I agree that a backup to GPS would be a wonderful thing. And I don't know how much it would cost, but eloran would be cheaper than launching another round of satellites and the signal would be stronger.

My point was that the "world" is embedding us further into GPS, to the point that if the unthinkable happened and the GPS system is corrupted, a lot of things, airliners in particular, are going to crash.

So, why aren't those using GPS for critical tasks demanding such a backup? Do they plan to fall back on GLONASS? The Russians would love that. Hunter is not the one to carry the banner, it should be those who are developing critical infrastructure with embedded GPS. Hunter ( in whose congressional district I reside,) is only there to get more money for the military. Where's the FAA, etc? The users need to support a backup. And I don't find any sign of that. The military have their encrypted signal, they couldn't care less..

Boris
 
Boris,
The aviation industry is continuing to maintain (at least to a degree) the Old VOR and current ILS systems. I suspect that these will still be part of the navigation systems for the foreseeable future.

I phones, Garmin and others are incorporating GLONASS in their GPS systems--Garmin has GLO, which is a separate GPS GLONASS receiver with Bluetooth for $99.

Europe has Galileo, and China BeiDou as their satellite navigation systems (and the Chinese with 35 satellites when complete may have some advantages over our GPS. But all of the GPS systems are subject to the same type of interference.

Absolutely the world is more embedded--and I neglected to mention the one of the most important and numerous applications, in the Cell phone for location services. I don't know if you watched the entire video, but Hunter is the one who kept bringing up eLoran while the CG admiral was a bit negative--after all Homeland Security KO'ed eLoran. (not sure if there is some vested political interest for Hunter).
 
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