posted 03-17-2012 07:49 AM ET (US)        

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LORAN-C has been around since World War II. I among many other aviators used it extensively in Vietnam, and frankly for many countries and users today it is still a totally adequate service. With USCG expertise and support for 52 years, LORAN-C provided unparalleled timing and navigation services around the United States and Canada until the pretender known as GPS came along and dethroned the aging monarch.

Now, that may sound like a natural sequence of events, except that LORAN-C was in metamorphosis, 80% of the way through the process actually, of morphing into a new digital (1990s era technology) LORAN know as eLORAN or enhanced LORAN with better, more reliable transmitters, smaller receivers, and a virtually jam-proof signal structure. Many likened the legacy eLORAN to a strong ground-based GPS with coded signals for security. All that was in place and 80% complete when the whole process was killed by an administration with a strong Luddite orientation and subsequently the bean counters pulled the plug in 2010, despite recommendations to complete eLoran from both the Department of Transportation’s Positioning and Navigation (PosNav) Committee and the Department of Homeland Security Geospatial Committee and the strong personal support of the DOT Undersecretary for Policy and the DHS Deputy Undersecretary for Preparedness and National Protection and Programs. My sources tell me the Office of Management and Budget (OMB) was determined to do away with Loran-C and facilitated its ultimate demise. An unfortunate theme we have seen played out much too often: Non-technical people forcing ill-advised technical decisions. In a country whose greatness has always been its technical acumen, willingness to take risks, and self-assurance, OMB stands as a chilling element of focus today…but, that’s a subject for a future article.

Since that time the U.S. Coast Guard spent more money dismantling the legacy LORAN-C infrastructure and antennas than it would have taken to complete the 20% upgrade for a full transition to eLORAN. Taking down the Port Clarence, Alaska, tower, the video of which was a YouTube favorite for many weeks, cost an estimated $8 million. The destruction of the towers in Attu, Shoal Cove and St. Paul were probably on average $5 million each. With the tower removal in Baudette, Minnesota, the cost of removing Loran towers to date cost close to $25 million. One could argue that the administration created some jobs in these “shovel-ready” tower tear downs, but I have no doubt that a better use of the funding would have been to deliver a robust positioning, navigation, and timing backup for the nation. But alas that is ancient history in the technology world, a whole 18 months to be exact.

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posted 03-18-2012 12:53 PM ET (US)         

I had Lowrance top of the line Loran on my boat, purchased new in 1989. It was expensive. I later found out it was highly inaccurate on Lat/Lon, which is how we identify where we are on this planet. When I tried to sell it 6 years later, I found it was obsolete and worthless and ended up throwing it in the garbage.

I had a large collection of waypoints, about 200, saved on my Loran, which also gave me the corresponding Lat/Lon positions. When I copied them over to my new Lowrance Differential GPS system, entered manually, I found they were HORRIBLY INNACURATE positions. Some were off as much as 2 miles and basically worthless. I had redo the entire
package.

It was also worthless in the Bahamas and some parts of Canada.

The manufacturers quickly stopped making these machines, and to 99% of boaters, the GPS systems are superior. The marketplace quickly determined that Loran could not compete with GPS for any number of reasons. We all knew Loran was dead. This was nothing new.

posted 03-18-2012 01:15 PM ET (US)            

LORAN and GPS actually determine position in almost exactly the same way and both systems are subject to exactly the same sort of errors. However, LORAN has a considerable advantage in that the precise location of its signal sources is fixed and extremely well-known, while in GPS the signal sources are satellites in orbit, whose precise position is subject to some variation from orbital mechanics and must be calculated very precisely on the fly. Both LORAN and GPS are subject to errors in signal propagation, but both can be corrected using similar techniques.

Position finding in both LORAN and GPS is done the same way, but in GPS devices we are now blessed with microcomputers that do all of the mathematics and calculating, giving us a latitude and longitude for position

When LORAN was operational there were NO low-cost micro-computers which could be used to produce instantaneous conversion of line of position based on delays into latitude and longitude. The conversion was done by the navigator using the LORAN time delays over-printed on charts.

LORAN positions were quite repeatable and the system accuracy was much higher than Larry's recollection of two-mile errors.

In the LORAN era there were no low-cost electronic chart plotters and no publicly available electronic cartography at any sort of price. There were no electronic chart plotters.

If the same advances in microprocessors and digital electronics were applied to a navigation system using LORAN, and if the LORAN signals themselves were increased in accuracy using modern techniques, and if a differential augmentation system like the FAA's space-based augmentation system WAAS were applied, LORAN could produce position fixes of an accuracy comparable to GPS. It could do this at a much lower operational cost--no billion-dollar spacecraft and billion-dollar rockets needed.

posted 03-18-2012 01:22 PM ET (US)            

This is one of the political absurdities of killing off LORAN. It cost a few pennies to run compared to GPS, and it was a benefit only to the USA. Instead we spend billions on GPS and let the entire globe use it for free. Many citizens do not realize that providing a free global navigation satellite system to the rest of the planet is actually one of the best ways to general goodwill toward the USA.

Another obvious benefit of LORAN was the very easy access to the signal sources for upgrades, repairs, and maintenance. LORAN stations are on the ground. You do not need to replace them every ten years. You do not need a space vehicle to get to a LORAN station.

posted 03-18-2012 01:42 PM ET (US)            

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Maybe this author has some political agenda?

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posted 03-18-2012 11:39 PM ET (US)         

"LORAN positions were quite repeatable and the system accuracy was much higher than Larry's recollection of two-mile errors"

As an example, I saved my Loran waypoints ON LOCATION, such as the Ft Lauderdale inlet, or the Chicago harbor entrance.
The Loran then showed those positions both as time delays from two towers, and translated it into Lat/Lon.

When I entered those same Lat/Lon positions in the GPS, I found they could be off as far as 2 miles. The Loran Lat/Lon positions were worthless. Almost none of the 200 were anywhere near accurate in Latitude and Longitude. Loran was lousy at Lat/Lon position on the surface of the earth, which was why it had to be discontinued. The GPS system gives highly accurate position in Lat/Lon, and from maybe 8 sources rather than two or three.

posted 03-19-2012 01:27 AM ET (US)            

The feeling I have is an overwhelming sense that this current administration is H&!! bent on destroying the past successes in almost every area and subject in America.
Loran is cheap and just as smart as carrying a second bullet while hunting, a spare tire while driving, or a life jacket while boating, Loran is and was a safety net, like one of those "donut" spare tires. Far from perfect, but it would still get you home. It was not free, and last time I checked either were bullets, spare tires or life jackets.

I suggest we all think really thoughtfully about our patriotism and our countries future. Think about our countless dead countrymen, who gave it all for our rights. Think about our nation a little bit more than only of ourselves.

posted 03-19-2012 08:16 AM ET (US)            

You can't ascribe to LORAN the failure of your computer algorithm to convert some observed time delays into a position. That is a failure of the computer algorithm you were using. LORAN time delays were quite accurately printed on government charts. If some device you owned could not convert them to latitude and longitude it was a shortcoming of the device, not of LORAN.

LORAN and GPS are both radio-locating systems, and work in similar manners. The location of the signal sources and the frequency of the signals are different. LORAN uses TDMA for the signals and GPS uses CDMA.

posted 03-19-2012 08:39 AM ET (US)            

One could cling to the obvious and not worth repeating benefits of a wired dial- up telephone as well, but we don't wax nostalgic about that device and maintain one for operational redundancy and superior audio performance.

Progress marches along, and perhaps this step is just one difference between a hypothetical President Great Grandfather McCain and the middle aged Obama, or perhaps this decision was all but a foregone conclusion based upon the proliferation and low expense of modern GPS.

posted 03-19-2012 11:03 AM ET (US)            

By the way, I can usually tell when someone calls my AT&T wired telephone from a modern, digital, VOIP telephone: the voice quality is bad, there is a lot of latency in the connection, and the connection is plagued with drop outs. So much for progress.

I prefer to keep the political speculation out of the discussion. For me, LORAN was a working system, already in place, that offered a low-cost alternative position finding and timing resource, which could have been very inexpensively upgraded.

posted 03-19-2012 12:24 PM ET (US)            

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PRJ said: "Don't be such a defeatist, gusgus, its all the little decisions made by people just like you that have created the world we live in, not any President's."

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I am neither a defeatist or pessimist. I am a realist. The difference is largely the facts surfacing daily in America, creating a true concern for my country.

Facts like jimh has reported in this thread are exposed every day and it seems they are all huge issues, like Loran. He brought up a good point, and even if your opinion of these facts are less important to you than they are to other Americans, they should be considered and discussed, long before their destruction.

This dismissal of any discussion is an Obama regime motis operandi, , supported far too often by the public.

LORAN is an old technology that is cheaply modernized as a country security system if our would becomes blinded by GPS aimed attacks. It is less than presidential to destroy any national navigation aid without discussion. Example; what item from the 1900's is mandatory in all aircraft, including jetliners? And why is it mandatory? (slang name) Whiskey Compass.

posted 02-28-2014 05:27 PM ET (US)            

See InsideGNSS magazine's article at:

http://www.insidegnss.com/node/3913

for more details. It mentions an important consideration: preservation of the legacy LORAN transmitter sites, which were located on ground whose electrical conductivity was very good for LF radio transmission. (All legacy LORAN was transmitted at 0.1-MHz using time-division multiple access methods.)

It seems hopeful that Congress will stop the Obama administration from tearing down more towers and selling off the transmitter sites. But you never know what the executive branch of government can do. Just ask the people who had planes at Chicago's Meig's Field. Now there was for a good example of the Chicago School of executive branch action.

http://en.wikipedia.org/wiki/Meigs_Field

posted 02-28-2014 09:27 PM ET (US)            

As one observer has noted, GPS is no longer a range location system but really a fundamental component of modern life, like having running water. An interruption or outage of GPS that lasts more than a few minutes would affect the entire nation in many ways other than having your recreational chart plotter lose its position data.

posted 03-01-2014 10:30 AM ET (US)            

Mr. Dana Goward gave interesting testimony which can be seen in a recording of the hearing available at

http://transport.house.gov/calendar/eventsingle.aspx?EventID=366184

Scrub forward in the recording to one-hour 33-minutes, when the panel reconvenes for its second session. In his opening remarks, Mr. Goward says, "And let me say, right off, mister chairman,..you are welcome to any of our meetings, any time.... Unlike the government, we are very open."

This remark is probably in reference to earlier testimony by a USCG rear admiral. When the panel asked the rear admiral about eLORAN, the rear admiral declined to answer in the open hearing, and cited concerns about those present possessing the necessary security clearance to have access to information about eLORAN or its status.

posted 03-03-2014 09:37 AM ET (US)            

A modern position locating receiver using eLORAN can provide an output of position in latitude and longitude coordinates, in precisely the same manner that a GPS receiver can. That position can be presented on an electronic chart display.

The accuracy of the position determined from a modern eLORAN receiver is suggested to be comparable to the accuracy of the position from an unaugmented GPS receiver solution. The accuracy of both systems, eLORAN and GPS, can be improved by separate augmentation systems. In the case of GPS, there are two augmentation systems which are operated as separate systems, the differential GPS system (DGPS) of the Coast Guard and the wide-area augmentation system (WAAS) of the Federal Aviation Administration. Similar augmentation systems could be employed to improve the accuracy of eLORAN, using similar methods to compensate for the similar problems. In both GPS and eLORAN there are inaccuracies introduced due to variations in the speed of propagation of the radio signals. Similar methods can be used to compensate in real time for these variations.

Perhaps you have forgotten that the accuracy of a GPS position fix was being intentionally degraded by use of Selective Availability (SA), and it was only in c.1996 that SA was ordered to be turned off, allowing civilian users of GPS to have improved precision in their position solutions. The appearance of the FAA's WAAS system is also fairly recent in GPS history. The WAAS augmentation became available initially in c.2003.

The combination of removal of SA and introduction of WAAS has upgraded GPS position fix accuracy significantly, and we now enjoy the benefit.

An eLORAN system of modern design should be able to provide position information of comparable accuracy, but there are other elements of eLORAN which are also important to understand. eLORAN can provide its signal to locations where GPS can never reach, such as inside of buildings. There is also much greater immunity to interruption of service from eLORAN because of the nature of its signals.

posted 03-03-2014 08:46 PM ET (US)            

You were probably using or looking at one of the early loran units that gave location information in TD (time differentials?) and there were TD lines on a chart. Sitex was an early brand, that I used, or attempted to use.

By the late 80's, early 90's, enough computing power was available to allow companies to develop units that made the conversion to L/L automatic.

I think my unit was a Northstar. It had repeatable accuracy of about 150'. I define repeatable accuracy as sitting at a dock, stable and not moving, noting the L/L and then attempting to return to the same location and noting just how close I could get.

posted 03-04-2014 11:05 AM ET (US)            

I have not made a survey of eLORAN receivers. I expect there are eLORAN receivers on the market, but they are aimed at commercial ships. I expect they are much more expensive than GNSS receivers.

The retail cost of a GNSS receiver is now down to the under $30 price range. There is a GNSS receiver in just about every smartphone on the market. I do not expect that eLORAN receivers will ever get to a price as low, nor will they become so compact they fit on a smartphone.

Re the politics: the change in direction of the government re eLORAN occurred coincident with the change in Executive Branch leadership. When the government takes a 180-degree turn in policy, I think it is more likely that change came from a top-down direction than from a bottom-up. For example, I don't think a bio-chemist in Ann Arbor decided to initiate a government policy on auto emission.

From what I can gather, I don't hold the Coast Guard culpable. They basically said something like this: Hey, we are spending some of our budget to run this LORAN operation, and we do not use it any more. Then the Executive Branch (pre-Obama) said, OK, announce that formally, and we'll let these other guys who want to run it and make it eLORAN take over. The Coast Guard did their part. They said they don't use it, and let us save our budget for some other stuff. The problem came when no funding was provided for another agency to take over and carry forward on the eLORAN.

I don't know that there was malice in the Obama administration neglecting to continue the eLORAN. Perhaps it was just an oversight or neglect. When they came into the Executive Branch, I am sure eLORAN was not on their agenda. When there was no budget for it, the progress stopped.

posted 03-04-2014 11:15 PM ET (US)            

I think the USCG has been trying to get out of the LORAN business for some time. The people that want eLORAN really want it as a back-up for navigation and as an alternative source of timing signals.

ASIDE on timing signals:

Since 1976 I have worked in an industry that needed very consistent time keeping. In our plant we had two master clocks that ran on crystal controlled time bases that were kept in a thermostatically regulated oven. We operated these like an old ship operated its chronometer: we never tried to adjust their setting. Pulses from one of these two master clocks drove all the secondary clocks in the plant. There were about 20 secondary clocks. We needed all the clocks to be in unison and to be accurate.

Our external-to-house primary time standard was the Naval Observatory in Washington, D.C. We set the secondary clocks to match that time. Back in the days when all telephones were on landlines, we would make a telephone call to the Naval Observatory. They have a telephone line that answers and lets you hear the time being announced with clicks. It is like listening to WWV on a radio. Over many years the master clocks would drift off from the external-to-house primary standard. We never reset them. We just used the pulses.

We would set all our secondary clock to the time from the Naval Observatory. We could easily add drop one second from all our secondary clock, add one second, or also jog the secondary clocks one hour plus or minus for daylight savings time, by using a little control panel on the master clocks. To lose time, it would just stop its output pulses for one second or one hour. To gain time, it would speed up its pulses to double the rate for the necessary interval.

posted 03-08-2014 01:23 PM ET (US)            

Image of a FAVAG 1-Hz pulse secondary clock:

http://www.chronometrophilia.ch/Electric-clocks/secFavagF00.jpg

FAVAG has a rich history in keeping time with electrical pulses. See

Horloges électriques (electric clocks)
http://www.chronometrophilia.ch/Electric-clocks/english.htm

Since they were Swiss-made, the clocks are rather durable and long lasting. Plus, a dial face clock with an accurate second hand is very handy in many timing situations. Better than a digital clock display.

There several specialized GPS receivers that provide a 1-Hz pulse output which is synchronized to the GPS time that is regulated with Cesium or atomic clocks.

Also note that GPS keeps its own time, different from UTC. We just use the pulses from the GPS receiver. But, as was my point in mentioning this, if the GPS constellation is not available, these secondary clocks and probably many others, will lose their primary clock reference.