World War II tech eLoran deployed as GPS backup in the UK

[John]

I came across this and wondered if anyone else had any input.
Plus if it's in the place on the forum, apologies.

World War II tech eLoran deployed as GPS backup in the UK

General Lighthouse Authorities (GLA) has announced that they have deployed a World War II technology called Long Range Navigation system, which they have named eLoran, in seven ports across Britain to serve as a backup for the existing Global Positioning System (GPS).

GLA notes that modern ships have a lot of equipment that rely on Global Navigation Satellite Systems for functioning and in case of failure the consequences will be disastrous. For this reason technology that doesn’t rely on the GPS was required as a backup. eLoran is a ground-based system rather than satellite-based and is designed to be used in the event of a GPS failure.

To give you a background of Loran, it was developed in the US and was a primary means of guiding US Navy warships through the battle raged Pacific. The system was quite successful and post-WWII era, the system was updated and crowned a new name Loran-C. The navigation system was adopted by mariners across the globe and was used until GPS was deployed.

Loran has now been renamed as eLoran because of the upgrades to the technology as well as the infrastructure. The more accurate system generates longwave radio signal, which is 1 million times more powerful than those from positioning satellites, are capable of reaching inside buildings, underground and underwater. According to GLA, eLoran and GPS are quite different from one another and hence there is no common mode of failure.

Installation of eLoran has already been concluded at seven ports along the east coast of Britain. The system is now in place in Dover, Sheerness, Harwich and Felixstowe, Middleborough, Leith, Humber and Aberdeen marking the completion of phase of the roll out.

Following the success of eLoran, several countries are already expressing interest in the technology and intend to benefit from GLA’s knowledge and experience of eLoran. South Korea is one of those countries who has already expressed interest in establishing an eLoran alliance with the UK.

[Scythe13]

Potentially a very invasive observation system if wrongly used. But it does make sense for it to be used in a GPS blackout.

No doubt there is better stuff to check out than little ol me. But such a system could well be employed to check whose hoarding food or something like that, if it's super sensitive. Just depends how portable they can be made.

[Mortblanc]

Are we talking about the same thing??

From what I read the LOREN system is a system of transmitters emitting a signal to be picked up by a receiver and used for navigation.

No mention of its ability to monitor anything, see anything or count your bean tins.

[Midnitemo]

Yeah I thought they were just high powered beacons transmitting so you can get a plot by using two and where they dissect hey presto that's where you are.

[CharlesHarris]

This link has useful technical info, they are looking at this for aviation also:

http://www.gps.gov/governance/advisory/m...narins.pdf

Loran-C Basics

• A hyperbolic radionavigation system…
– …operating between 90 kHz and 110 kHz…
– …that uses a very tall antenna…
– …that broadcasts primarily a groundwave
– …at high power…
– …that provides both lateral position…
– …and a robust time and frequency standard

• Previously in the US:
– A supplemental system for en route navigation in the US National Airspace System (NAS)
– A system for maritime navigation in the coastal confluence zone (CCZ)/Economic Exclusion Zone (EEZ)
– A Stratum 1 frequency standard (i.e., 1 x 10-11) that also provides time within 100ns of UTC (USNO

“The (US) Government is evaluating the ability of an enhanced Loran system to support non-precision
approach for aviation users, harbor entrance and approach for maritime users, and improved
performance for time and frequency users. If the Government concludes as a result of the evaluations
that Loran-C is not needed or is not cost effective, the United States Coast Guard (USCG) will plan to
disestablish the system by the end of fiscal year 2008 with appropriate public notice.”

The Loran Evaluation Specifics
• Determined whether an enhanced Loran (eLoran) system could provide the:
– Accuracy
– Availability
– Integrity
– Continuity
a) to support Lateral Navigation through all phases of flight – including NonPrecision Approach (NPA)
b) to support Harbor Entrance and Approach (HEA) for maritime users
• Determined what other ancillary benefits could be derived from the continued provision of enhanced Loran services
– e.g., to support Stratum 1 frequency and timing users
• Determined if providing these services via eLoran would be cost beneficial

Report Executive Summary

• The report documented the FAA-led Team’s Loran evaluation program results as requested by the DOT Undersecretary for
Policy in his role as the Chair of the DOT Positioning and Navigation Committee.
• The government agency, industry, and academic evaluation team focused on determining whether Loran could meet aviation and maritime radionavigation, and time/frequency application requirements, thus providing a viable, cost-effective alternative to the GPS in the event of a GPS outage.
• Applications evaluated included aviation navigation through nonprecision approach (NPA) operations, maritime navigation through harbor entrance and approach (HEA) operations, and time and frequency distribution through the Stratum 1 level.

The Evaluation Team’s Conclusion

“The evaluation shows that the modernized Loran system could satisfy the current NPA, HEA, and
timing/frequency requirements in the United States and could be used to mitigate the operational
effects of a disruption in GPS services, thereby allowing the users to retain the benefits they derive
from their use of GPS.”

“This conclusion is based on an analysis of the applications’ performance requirements; expected modification of radionavigation policies, operating procedures, transmitter, monitor and control processes, and user equipment
specifications; completion of the identified Loran-C infrastructure changes; and results from numerous field tests. Collectively, these create the architecture for the modernized Loran system.”

Conclusions

1. “eLoran is the best available backup provider to GPS as a reference source for precise time synchronization and frequency control.”
2. “With its large coverage area, its high level of redundancy due to multiple transmitters, and its ability to be received indoors eLoran also has the potential to become a leading provider of time-of-day information in the United
States, a role that legacy Loran could not fulfill.”

Why eLoran?

• eLoran meets needs of identified critical applications – and others
– 10-20 meter accuracy for harbor entrance
– 0.3 nautical mile required navigation performance (RNP 0.3)
– Stratum 1 for time & frequency users – 50 ns time accuracy

• eLoran is NOT 1958 Loran-C
– New infrastructure – solid state transmitters, state-of-the-art time & frequency equipment, uninterruptible power supplies
– New operating concepts – time of transmission, all-in-view signals, message channel with differential corrections, integrity, etc.
– New user equipment - digital, processes eLoran & GPS signals interchangeably, compact H-field antennas to eliminate “p-static”

• eLoran upgrade & 20 year ops affordability
– $159M invested to date – nonrecurring $17-25M/yr

• Additional $143M will complete eLoran – 5-8 years at current funding level
– Ops & maintenance currently $37M/yr – recurring
• Reduce routine O&M costs with eLoran efficiencies – apply savings to identified major maintenance backlog ($289M
– Avoid $146M costs of decommissioning existing Loran-C infrastructure

Conclusions and Recommendations

• Reasonable assurance of national PNT availability is prudent & responsible policy
– For critical safety of life & economic security applications
– And for all other “quality of life” applications

• eLoran is a cost effective backup – to protect & extend GPS – for identified critical (& other GPS-based) applications
– Interoperable & independent
– Different physical limitations & failure modes
– Seamless operations & GPS threat deterrent

• Given US Government support, anticipate users will equip with eLoran as the backup of choice
– International community looking for US leadership

• Recommend complete eLoran upgrade & commit to operate for 20 years
– Affordable within recent funding history

Loran Stations in Northern Europe (9) All Stations Used in a Prototype eLoran Mode
• United Kingdom
– Anthorn
• France
– Lessay
– Soustons
– Brest ( Control Centre)
• Germany
– Sylt
• Denmark
– Ejde
• Norway
– Berlevag
– Bo
– Jan-Mayen
– Vaerlandet

Northern European Loran Station Status

• United Kingdom
– Anthorn Station built at low cost/operated at low cost commercially through contract with General Lighthouse Authorities of the UK and Ireland
• Costs spread across multiple UK Gov’t Agencies
• Coordinated by Centre for the Protection of National Infrastructure (Cabinetlevel organization)
– Used nationally for precise timing and by a Gov’t agency for secure data
– Finances continued operation of Sylt station (Germany)
– Fully supportive of eLoran as a PNT alternative to GNSS

• France
– Lessay and Soustons Stations and Brest Control Centre operated by French DCNS
– Current economic situation/politics is putting continuation of current stations in jeopardy
• No decision had been made
• Gov’t under positive pressure from commercial interests, including telecom sector
• Significant interest in commercial operation of the system

• Germany
– Continues to operate Sylt station financed in part by UK

• Denmark
– Continues to operate Ejde Station financed by France

• Norway
– Has announced that the Gov’t intends to discontinue its Loran-C
operations in 2016

• Support of Loran has changed a number of times over the years depending on the Government

• The Netherlands
– Has no stations, but testing highest accuracy enhanced differential Loran (eDLoran) to ensure efficiency and capacity in the Port of Rotterdam
– Extreme support for the need for eLoran to ensure continuation of operations in the event of a GNSS service disruption

Chayka Stations in Western Russia (9)

• Chayka stations compatible with Loran-C
• Currently in discussions with UK as means to develop eChayka compatible with eLoran
• Russia currently investigating upgrade of Eastern Stations:
• Big driver is coverage of high north shipping
– Bryansk -- Simferopol
– Inta -- Slonim
– Norilsk -- Syzarin
– Pankratyev -- Petrozavodsk
– Tumanny

and Five More in Eastern Russia
– Tamylar
– Okhotsk
– Alexandrovsk
– Petropavlovsk
– Ussuriisk

Loran Stations in China (6) , Korea (2), and Japan (4)

• China
– Possibly in process of upgrading all stations to an eLoran solution
• Japan
– Announced that they intend to shut down stations in near future
– Situation remains fluid

• China
– Chongzuo
– Hexian
– Raoping
– Xuancheng
– Rongcheng
– Helong

• Japan
– Gesashi
– Niijima
– Tokachibuto
– Minnamitorishima

Loran Stations in Korea (2)
• Korea
– Pohang
– Kwangju

Korea Recognizes that “Global Navigation Satellite Systems (GNSS) have vulnerabilities to intentional and
unintentional interference and that a complementary system is needed for resiliency”*
– Recognizes that “eLoran is the only proven electronic system that can provide such resiliency”*
– Upgrading and expanding eLoran coverage
• Phased approach
– First upgrade current two stations and add one additional station
• Up to total of five stations
– Driven by land-mobile requirements
* Jiwon Seo and Je-Bong Oh, “Update on the Korean eLoran Program,” 2014 ENC

Revised Korean eLoran Program
• Two phase approach
– Implement maritime eLoran for the West Sea of Korea with 3 transmitters and 2 differential stations by the end of 2015
– If demonstrated performance is satisfactory, deploy more transmitters and differential stations to cover other areas
• Phase 1
– Upgrade existing two Loran-C transmitters to eLoran operation
• Pohang (150 kW)
• Kwangju (50 kW)
– Deploy a 250 kW eLoran transmitter at Ganghwa
– Deploy two differential eLoran stations at locations proposed by contractor
– Provide 20 m maritime accuracy within 30 km of differential stations

eLoran Stations in Saudi Arabia (5)
• Saudi Stations all upgraded to eLoran capable (Eurofix) standard
• Working on tender for eLoran receivers
– Government has considered making eLoran required equipage for Red Sea transits
• Very interested in landmobile/time applications
– Afif
– Al Khamasin
– Al Muwassam
– Ash Shaykh
– Salwa

Loran Stations in India (6)
• Two “mini-chains” providing coverage to ports on east and west coasts
– Veraval
– Billimora
– Dhrangadhara
– Diamond Harbor
– Balasore
– Patpur
• Government considering phased expansion of eLoran coverage
– Perhaps an additional 11 stations
• Upgrade of existing stations

[Mortblanc]

When it is all simplified into language we can understand the system operates as a set of beacons we can use to "triangulate in reverse".

We can find three signals, loop three circles around the associated beacons and the intersection of the three circles is our location. Like a very precise vin diagram that gives position down to a few meters.

[Straight Shooter]

Well that is concise enough for me MB....thank you.

[Jonas]

The GPS satellites are nearing the end of their expected service life, and the US, frankly, can't afford to replace these as fast as they will probably burn out. Add in the fact that GPS satellites are vulnerable to attack from PRC anti-sat missiles, and Loran C stations, which are land based, make a good alternative. Kudos to the Brits for looking ahead.

[Geordie_Rob]

I hope gps doesn't crash any time soon. I just paid £100 for a new sat nav 2 weeks ago

[River Song]

I Must learn how to use my compass and a map -- seriously