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Author Topic:   Differential eLORAN Working In Europe
jimh posted 05-04-2014 11:18 AM ET (US)   Profile for jimh   Send Email to jimh  
A new navigation and position system is operational in Europe in the area around the port of Rotterdam, and it uses the decades-old LORAN signals to provide position accuracy comparable to GPS. The system is called enhanced diffferential Loran or eDLoran. It provides a source of position and navigation completely independent of satellite based GNSS systems such as GPS or GLONASS.

The eDLoran system was developed by the Netherlands Pilot Association and electronics manufacturer Reelektronika BV. The pilots now carry with them a small, portable, eDLoran receiver, which provides position and navigation information with an accuracy of better than 5-meters.

No modification of the existing eLORAN transmitters in England, France, and Germany was required. The real-time data for the differential information is apparently sent via the GPRS (cellular telephone) mobile network.

It seems rather odd to me that in the USA, the Department of Homeland Security, with a budget of billions of dollars, is going around blowing up LORAN stations, and in Europe, a small pilot's association, working with a electronics manufacturer, has implemented a working differential eLORAN system with accuracy comparable to GPS.

Going forward, one has to figure that it will cost the USA about $1-billion for each GPS satellite in orbit. For GPS to work as planned, 32 satellites are needed in orbit and in operational status.

The projected cost savings of blowing up our existing LORAN towers, dismantling the stations, and selling off the land was supposed to be perhaps $20-milion, but, in actual outcome, has turned out to be much more costly than just continuing to operate them. Destroying our LORAN capability was more expensive than maintaining it.

Sources:
http://www.rin.org.uk/News.aspx?ID=378&SectionID=0&ItemID=3316
http://www.insidegnss.com/node/3838

Highly recommended technical presentation:
http://rntfnd.org/wp-content/uploads/eDLoranReelektronika-Presentation. pdf

ASIDE: Re the above technical presentation, an interesting point is presented. Because of the frequency of LORAN (100-kHz) the antenna structures themselves are rather large, often larger than the position resolution of the system (about 15-feet). This raises the question of where is the actual phase center of the signal emitted from such a large antenna. Some of the LORAN transmitter antennas are top-loaded verticals with a rather wide top hat.

jimh posted 05-15-2014 10:56 AM ET (US)     Profile for jimh  Send Email to jimh     
Noted GPS commentator Don Jewell remarks on the eDLoran achievement in Rotterdam in his GPS World magazine column at

http://gpsworld.com/dloran-surprise-european-navigation-conference-2014/

jimh posted 11-04-2014 12:15 PM ET (US)     Profile for jimh  Send Email to jimh     
An article from the website of PHYSICS.ORG announced that eLORAN is now deployed to an initial operating capability in the United Kingdom, making the U.K. the first maritime nation to roll out this improved radio navigation system.

See

http://phys.org/news/2014-11-uk-eloran-gps-backup-safe.html

for details. Thanks to David H. (HOOSIER) for mentioning this article.

Mariners should recall that the United States of America (USA) was about 80-percent of the way toward upgrading the Coast Guard LORAN navigation system to eLORAN when the Obama Administration made a policy decision to cut off funding. Only $13-million was needed to complete the eLORAN system. Instead, the federal government under Obama embarked on a very expensive program of dismantling and removing LORAN stations and selling of the land they occupied. This dismantling program cost more than the $13-million estimated to complete the transition to eLORAN. The sites of the LORAN transmitter stations were on very special ground, typically chosen for excellent ground conductivity to enhance the transmission of low-frequency radio signals, and were going to be sold off (probably to subsidized farmers that would grow corn on them with federal subsidy to make ethanol gasoline to be sold with federal subsidy--that is some system, eh?)

Other nations, have avoided following the absurd path of the USA, and are maintaining and improving their LORAN systems.

To put the $13-million cost of upgrading the USA LORAN to eLORAN in perspective, a one-time-only non-reusable RD-180 rocket booster engine used to launch one GPS satellite costs about that much. Of course, that is only a small portion of the total cost to launch one GPS satellite.

jimh posted 01-18-2015 12:51 AM ET (US)     Profile for jimh  Send Email to jimh     
Earlier this week the government of the USA published a request for information by the Department of Defense to potential suppliers for information on development and delivery of 50,000 eLORAN receivers. The notice asks for replies by early February 2015.

The REQUEST FOR INFORMATION can be read at

https://www.fbo.gov/index?s=opportunity&mode=form& id=e214da2400423b0fa3e67d51ca606a6c&tab=core&_cview=0

An article on the website INSIDEGNSS.COM has some informed commentary on what this request for information might portend. See

http://www.insidegnss.com/node/4372

The article comments:

quote:
The [request for information] came out as civil and military officials prepared to meet to develop a concept of operations for an eLoran system in the United States. When done, the CONOPS document will lay out how the system will be operated and by whom. A source familiar with the effort said it is a necessary step before deciding whether to undertake the program and will help determine what the system will cost.

In the past year, support has blossomed again for eLoran in other nations, on Capitol Hill, and among industry and section of the navigation community. Most approaches would repurpose some of the remaining assets of the old Loran system, which President Obama ordered to be discontinued in 2010.


GPSWORLD.COM is also covering this story. See their reaction at

http://gpsworld.com/ u-s-army-interested-in-eloran-pnt-for-the-warfighter/

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