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eLORAN: Inside the Government's Backup Plan for GPS Failure



 
 
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  #1  
Old June 12th 08, 01:00 AM posted to sci.geo.satellite-nav,rec.aviation.military,rec.aviation.piloting
Soldier in a Combat Zone
external usenet poster
 
Posts: 11
Default eLORAN: Inside the Government's Backup Plan for GPS Failure

Lets look at what we have here. Currently we have the Global
Navigation Satellite System (GNSS or GPS). Most of us are now familiar
with this technology. But are you aware of WAAS (wide area
augmentation system)? This is a system on the satellite that makes
corrections so that the data is more accurate on your GPS receiver.
Differential GPS (DGPS) is a system that is similar to LORAN (ran by
the Coast Guard) that provides data correction in parallel with your
GPS. What all of these systems (WAAS, DGPS) do is take a known
location, compare that to the GPS data then transmit the corrections.

We see survey equipment that provides localized DGPS for survey teams
(and centimeter accuracy).

Aviation is moving to LAAS (local area augmentation system) that would
provide very accurate data so that aircraft can land under poor
visibility.

The Navy has systems in development for ships and this technology is
moving towards the civilian market as a replacement for ILS (IFR Cat
I, II, III landings).

VORTAC is going away, along with ILS. They are scheduled to be
replaced by a GPS/LAAS (local area augmentation system) combination.
LORAN-C was scheduled to go away however this new eLORAN looks to
merge DGPS and a ground based version of GPS (eLORAN) that could
augment GPS. We use old LORAN-C frequencies now for DGPS (100 KHz
system coupled with 1500 MHz GPS).

From what I have been able to read, eLORAN will be somewhat different
than LORAN-C. Instead of a master and several slaves, the new system
will be like GPS in that several stations are used by measuring the
time difference from each. Instead of a master-slave in a chain,
eLORAN uses all stations that your receiver can hear (like GPS can use
all satellites in view). It appears that it will provide DGPS services
as well.

Europe is pushing eLORAN due to the control of the GNSS by the US
military.

It is a cheaper, land based system that is in the control of many
nations.

Harder for terrorists to jam or destroy. Frequencies are between
90-110 KHz with transmitters at 1000 Watts to 1 MW. GPS is about 1500
MHz and milliwatts.

Here are some links that might provide more information. The Coast
Guard site has pages on GPS, DGPS and eLORAN.

http://www.navcen.uscg.gov/eLoran/overview.htm

http://www.torkildsen.no/Navconf2007/Offermans.pdf

http://www.locusinc.com/pdf/Loran%20...0w%20logo6.pdf

http://www.locusinc.com/library/2005%20RTCM_Locus.pdf

http://www.askhelios.com/ERNP/docume...t%20300606.ppt

http://www.mycoordinates.org/satelli...uthnmyths1.php

http://www.popularmechanics.com/tech...y/4266972.html

Inside the Government's Backup Plan for GPS Failure

With the threat of everything from antisatellite weapons to solar
flares, the Department of Homeland Security is upgrading an old
navigation system to eLORAN to track signals across the country, Lost-
style.

LORAN Station, Attu, Alaska: This is the view from the 600-ft. LORAN
tower.

By Joe Pappalardo

Published on: June 3, 2008

Satellite-based navigation has become a ubiquitous tool for business,
military and personal use. The downside is that any disruption in the
Global Positioning System could wreak havoc down on Earth.

This year, the Department of Homeland Security decided that a 30- year-
old navigation system used by mariners will be upgraded to back up
GPS. The decision preserves the Long-Range Aids to Navigation

(LORAN) network, which has been teetering on the verge of forced
retirement since the 1980s, according to the Coast Guard's Navigation
Center.

The backbone of LORAN is a network of transmission stations, many
located in remote regions, staffed with Coast Guard personnel, and
equipped with antennas as tall as 900 ft.

The 2009 DHS budget allocates $34.5 million for the Coast Guard to
start upgrading the LORAN system with modern electronics and solid-
state transmitters. Users of the enhanced system, called eLORAN, will
acquire and track signals from ground stations in much the same way
they triangulate signals from multiple satellite feeds.

LORAN also adds a data channel that can handle more detailed
information.

The system won't just wait for GPS to fail: eLORAN stations will
continually transmit time-keeping data needed for navigation and
warnings about coming disruptions.

Why GPS Needs a Backup Plan

Intentional Jamming

Threat: GPS signals use low-powered, high-frequency signals that are
easy to block.

eLORAN Fix: Uses high-powered transmitters that send stronger signals
requiring more power to disrupt.

Environmental Interference

Threat: Signals from GPS sats need to be in the line of sight of
receivers and are blocked by metal, mountains and reinforced concrete.

eLORAN Fix: Terrestrial signals bend around the Earth's curvature and
can penetrate urban canyons and dense foliage.

Cosmic Radiation

Threat: Unusually large solar flares can produce radio bursts over the
same frequency bands as GPS satellite transmissions.

eLORAN Fix: Cosmic radio waves cannot penetrate the ionosphere, so
LORAN signals are immune to interference.

Antisatellite Weapons

Threat: Future ground-based missiles could target and knock out GPS
satellites.

eLORAN Fix:Ground stations can be more easily guarded from attacks,
including those by missiles.


  #2  
Old June 12th 08, 07:53 AM posted to sci.geo.satellite-nav,rec.aviation.military,rec.aviation.piloting
Biff Clinton
external usenet poster
 
Posts: 4
Default eLORAN: Inside the Government's Backup Plan for GPS Failure

Soldier in a Combat Zone wrote:
Lets look at what we have here. Currently we have the Global
Navigation Satellite System (GNSS or GPS). Most of us are
now familiar
with this technology. But are you aware of WAAS (wide area
augmentation system)

Clinton ordered the induced DOD error rendering the FAA WAAS
no longer required. The result was a massive waste of tax
money and resources not to mention the FAA's very poor
management of the WAAS program resulting in more waste

The FAA and Government was forced to put a happy face
on the entire WAAS program even though with one stroke of a
pen Clinton made the WAAS system no longer required.

This is a system on the satellite that makes
corrections so that the data is more accurate on your GPS
receiver.
(No longer required after Clinton ordered the removal of DOD
induced error)

Differential GPS (DGPS) is a system that is similar to LORAN
(ran by
the Coast Guard) that provides data correction in parallel
with your
GPS. What all of these systems (WAAS, DGPS) do is take a known
ocation, compare that to the GPS data then transmit the
corrections.

We see survey equipment that provides localized DGPS for
survey teams
(and centimeter accuracy).

Aviation is moving to LAAS (local area augmentation system) that would
provide very accurate data so that aircraft can land under poor
visibility.


The LAAS is a good system with a a major fatal flaw
It has single thread weakness. The uplink correction signal
is broadcast on VHF frequencies. If you jam the uplink(One
10 watt frequency) you render the LAAS unusable. Most areas
will have only one LAAS master station and major terminal
areas like Southern Cal or Atlanta will have two.

Two VHF jammers. No more LAAS. No more landings during IFR

Very Bad

The Navy has systems in development for ships and this
technology is
moving towards the civilian market as a replacement for ILS
(IFR Cat
I, II, III landings).


LAAS will never replace CAT 2 or 3 ILS as long as you can
jam the LAAS uplink. Combination GPS/LAAS/RNAV will probably
replace CAT1 however

Imagine a heavy with 350 souls on board on final so low he
can't spool up in time for a missed approach when that LAAS
uplink disappears with no LOC or GS signal?

Not good

VORTAC is going away,


Most of the 650 or so VORTAC's will be decommissioned but a
skeleton network of about 150 will remain until 2030


along with ILS. They are scheduled to be
replaced by a GPS/LAAS (local area augmentation system) combination.
LORAN-C was scheduled to go away however this new eLORAN looks to
merge DGPS and a ground based version of GPS (eLORAN) that could
augment GPS. We use old LORAN-C frequencies now for DGPS (100 KHz
system coupled with 1500 MHz GPS).


Low frequency navigation signals are interfered with during
solar or night time ionosphere activity and do not make good
stand alone navigation signals

Yep GPS and this whiz bang stuff is real cool huh!!

Just imagine a terrorist group releasing at random all over
America balloons with GPS jammers. Powered by DC batteries
and drifting with the wind. Random. In mass.

Thousands of them built for less than a $100 apiece. The GPS
system and the airline's and the railroads and trucking and
shipping and the thousands of other systems dependent on GPS
signals or clocks will be frozen in it's tracks.The sad
thing is the Government would be powerless to stop it.

GPS signals from space by the time they get to Earth are
down in the -140 dBm area of power in the radio spectrum.
Itsy Bitsy little signals yanked out of the spectrum mud.

A firefly fart can jam -140 signals.

Thousands of balloons with little 1 watt GPS jammers
dangling from them.(1 watt is 100 TRILLION times more watts
than -140 dBm). 1 watt can be produced for a few hours with
a 9 volt battery

Disposable throw away jammers. Drifting with the wind.
Thousands of them. For days and days. Coming from all
corners of America.

It would not be good.

A little money and some radio shack geeks could shut it
down. BTW how many terrorists did it take to change history
back on 9/11?

All this fancy technology is real neat. Until it drives us
off a cliff

In summary?

WAAS is a waste and no longer required
LAAS is single threaded aka FATAL FLAW
LORAN sucks at night or during solar flares

I think we better figure out a way to take the GPS and LAAS
signals and re-broadcast it in a cellular pattern with
multiple ground stations on multiple frequencies with 100 to
1000 watt ground stations.

The current LAAS design is weak and easily disabled by
intelligent jamming and spoofing

First rule of critical design
Redundancy(Cubed)



From what I have been able to read, eLORAN will be somewhat different
than LORAN-C. Instead of a master and several slaves, the new system
will be like GPS in that several stations are used by measuring the
time difference from each. Instead of a master-slave in a chain,
eLORAN uses all stations that your receiver can hear (like GPS can use
all satellites in view). It appears that it will provide DGPS services
as well.

Europe is pushing eLORAN due to the control of the GNSS by the US
military.

It is a cheaper, land based system that is in the control of many
nations.

Harder for terrorists to jam or destroy. Frequencies are between
90-110 KHz with transmitters at 1000 Watts to 1 MW. GPS is about 1500
MHz and milliwatts.

Here are some links that might provide more information. The Coast
Guard site has pages on GPS, DGPS and eLORAN.

http://www.navcen.uscg.gov/eLoran/overview.htm

http://www.torkildsen.no/Navconf2007/Offermans.pdf

http://www.locusinc.com/pdf/Loran%20...0w%20logo6.pdf

http://www.locusinc.com/library/2005%20RTCM_Locus.pdf

http://www.askhelios.com/ERNP/docume...t%20300606.ppt

http://www.mycoordinates.org/satelli...uthnmyths1.php

http://www.popularmechanics.com/tech...y/4266972.html

Inside the Government's Backup Plan for GPS Failure

With the threat of everything from antisatellite weapons to solar
flares, the Department of Homeland Security is upgrading an old
navigation system to eLORAN to track signals across the country, Lost-
style.

LORAN Station, Attu, Alaska: This is the view from the 600-ft. LORAN
tower.

By Joe Pappalardo

Published on: June 3, 2008

Satellite-based navigation has become a ubiquitous tool for business,
military and personal use. The downside is that any disruption in the
Global Positioning System could wreak havoc down on Earth.

This year, the Department of Homeland Security decided that a 30- year-
old navigation system used by mariners will be upgraded to back up
GPS. The decision preserves the Long-Range Aids to Navigation

(LORAN) network, which has been teetering on the verge of forced
retirement since the 1980s, according to the Coast Guard's Navigation
Center.

The backbone of LORAN is a network of transmission stations, many
located in remote regions, staffed with Coast Guard personnel, and
equipped with antennas as tall as 900 ft.

The 2009 DHS budget allocates $34.5 million for the Coast Guard to
start upgrading the LORAN system with modern electronics and solid-
state transmitters. Users of the enhanced system, called eLORAN, will
acquire and track signals from ground stations in much the same way
they triangulate signals from multiple satellite feeds.

LORAN also adds a data channel that can handle more detailed
information.

The system won't just wait for GPS to fail: eLORAN stations will
continually transmit time-keeping data needed for navigation and
warnings about coming disruptions.

Why GPS Needs a Backup Plan

Intentional Jamming

Threat: GPS signals use low-powered, high-frequency signals that are
easy to block.

eLORAN Fix: Uses high-powered transmitters that send stronger signals
requiring more power to disrupt.

Environmental Interference

Threat: Signals from GPS sats need to be in the line of sight of
receivers and are blocked by metal, mountains and reinforced concrete.

eLORAN Fix: Terrestrial signals bend around the Earth's curvature and
can penetrate urban canyons and dense foliage.

Cosmic Radiation

Threat: Unusually large solar flares can produce radio bursts over the
same frequency bands as GPS satellite transmissions.

eLORAN Fix: Cosmic radio waves cannot penetrate the ionosphere, so
LORAN signals are immune to interference.

Antisatellite Weapons

Threat: Future ground-based missiles could target and knock out GPS
satellites.

eLORAN Fix:Ground stations can be more easily guarded from attacks,
including those by missiles.


  #3  
Old June 12th 08, 05:27 PM posted to sci.geo.satellite-nav,rec.aviation.military,rec.aviation.piloting
Bob Gardner
external usenet poster
 
Posts: 315
Default eLORAN: Inside the Government's Backup Plan for GPS Failure

Enhanced loran uses the H field and is not subject to the night and skywave
errors of classic loran. Users of enhanced loran will have to install new
antennas. I have seen a combination eLoran-GPS antenna at the headquarters
of Locus, Inc., developers of the all-in-view receiver, and it is about the
size of a flat SDF antenna. Go to www.crossrate.com to see eLoran sets
designed for maritime use.

It would be nice if you didn't append the complete text of all prior
messages to your own message.

Bob Gardner

  #4  
Old June 12th 08, 05:50 PM posted to sci.geo.satellite-nav,rec.aviation.military,rec.aviation.piloting
Jon
external usenet poster
 
Posts: 194
Default eLORAN: Inside the Government's Backup Plan for GPS Failure

On Jun 12, 12:27 pm, "Bob Gardner" wrote:
Enhanced loran uses the H field and is not subject to the night and skywave
errors of classic loran. Users of enhanced loran will have to install new
antennas. I have seen a combination eLoran-GPS antenna at the headquarters
of Locus, Inc., developers of the all-in-view receiver, and it is about the
size of a flat SDF antenna. Go towww.crossrate.comto see eLoran sets
designed for maritime use.


We've had the SatMate in the lab for a few years. Nice box.

http://www.locusinc.com/satmate.html

It would be nice if you didn't append the complete text of all prior
messages to your own message.


Thanks for doing so, especially his reply

Bob Gardner


Regards,
Jon
  #5  
Old June 13th 08, 01:13 AM posted to sci.geo.satellite-nav,rec.aviation.military,rec.aviation.piloting
Soldier in a Combat Zone
external usenet poster
 
Posts: 11
Default eLORAN: Inside the Government's Backup Plan for GPS Failure

LAAS most likely will be done based on the Navy system that is spread
spectrum, frequency hopping, thus more resistant to jamming. The FAA
would have access to the protected (P) mode which also is SS/FH and
encrypted. So I do not worry about jamming.

As for eLORAN, look at the article. Coast Guard is big into this.
This is a Link to their site. And the Europeans are looking to use
this rather than spend billions on a satellite based system. Much of
the poorer countries can afford one or two site of eLORAN and be
independent of the US Air Force control of GPS.
On
Jun 12, 2:53 am, Biff Clinton wrote:
Soldier in a Combat Zone wrote:

  #6  
Old June 13th 08, 01:15 AM posted to sci.geo.satellite-nav,rec.aviation.military,rec.aviation.piloting
Soldier in a Combat Zone
external usenet poster
 
Posts: 11
Default eLORAN: Inside the Government's Backup Plan for GPS Failure

Inside the Government's Backup Plan for GPS Failure

With the threat of everything from anti-satellite weapons to solar
flares, the Department of Homeland Security is upgrading an old
navigation system to eLORAN to track signals across the country, Lost-
style.

LORAN Station, Attu, Alaska: This is the view from the 600-ft. LORAN
tower.

By Joe Pappalardo

Published on: June 3, 2008

Satellite-based navigation has become a ubiquitous tool for business,
military and personal use. The downside is that any disruption in the
Global Positioning System could wreak havoc down on Earth.

This year, the Department of Homeland Security decided that a 30- year-
old navigation system used by mariners will be upgraded to back up
GPS. The decision preserves the Long-Range Aids to Navigation

(LORAN) network, which has been teetering on the verge of forced
retirement since the 1980s, according to the Coast Guard's Navigation
Center.

The backbone of LORAN is a network of transmission stations, many
located in remote regions, staffed with Coast Guard personnel, and
equipped with antennas as tall as 900 ft.

The 2009 DHS budget allocates $34.5 million for the Coast Guard to
start upgrading the LORAN system with modern electronics and solid-
state transmitters. Users of the enhanced system, called eLORAN, will
acquire and track signals from ground stations in much the same way
they triangulate signals from multiple satellite feeds.

LORAN also adds a data channel that can handle more detailed
information.

The system won't just wait for GPS to fail: eLORAN stations will
continually transmit time-keeping data needed for navigation and
warnings about coming disruptions.

Why GPS Needs a Backup Plan

Intentional Jamming

Threat: GPS signals use low-powered, high-frequency signals that are
easy to block.

eLORAN Fix: Uses high-powered transmitters that send stronger signals
requiring more power to disrupt.

Environmental Interference

Threat: Signals from GPS sats need to be in the line of sight of
receivers and are blocked by metal, mountains and reinforced concrete.

eLORAN Fix: Terrestrial signals bend around the Earth's curvature and
can penetrate urban canyons and dense foliage.

Cosmic Radiation

Threat: Unusually large solar flares can produce radio bursts over the
same frequency bands as GPS satellite transmissions.

eLORAN Fix: Cosmic radio waves cannot penetrate the ionosphere, so
LORAN signals are immune to interference.

Antisatellite Weapons

Threat: Future ground-based missiles could target and knock out GPS
satellites.

eLORAN Fix:Ground stations can be more easily guarded from attacks,
including those by missiles.

Lets look at what we have here. Currently we have the Global
Navigation Satellite System (GNSS or GPS). Most of us are now familiar
with this technology. But are you aware of WAAS (wide area
augmentation system)? This is a system on the satellite that makes
corrections so that the data is more accurate on your GPS receiver.
Differential GPS (DGPS) is a system that is similar to LORAN (ran by
the Coast Guard) that provides data correction in parallel with your
GPS. What all of these systems (WAAS, DGPS) do is take a known
location, compare that to the GPS data then transmit the corrections.
We see survey equipment that provides localized DGPS for survey teams
(and centimeter accuracy).

Aviation is moving to LAAS (local area augmentation system) that would
provide very accurate data so that aircraft can land under poor
visibility.

The Navy has systems in development for ships and this technology is
moving towards the civilian market as a replacement for ILS (IFR Cat
I, II, III landings).

VORTAC is going away, along with ILS. They are scheduled to be
replaced by a GPS/LAAS (local area augmentation system) combination.
LORAN-C was scheduled to go away however this new eLORAN looks to
merge DGPS and a ground based version of GPS (eLORAN) that could
augment GPS. We use old LORAN-C frequencies now for DGPS (100 KHz
system coupled with 1500 MHz GPS).

From what I have been able to read, eLORAN will be somewhat different
than LORAN-C. Instead of a master and several slaves, the new system
will be like GPS in that several stations are used by measuring the
time difference from each. Instead of a master-slave in a chain,
eLORAN uses all stations that your receiver can hear (like GPS can use
all satellites in view). It appears that it will provide DGPS services
as well.

Europe is pushing eLORAN due to the control of the GNSS by the US
military.

It is a cheaper, land based system that is in the control of many
nations.

Harder for terrorists to jam or destroy. Frequencies are between
90-110 KHz with transmitters at 1000 Watts to 1 MW. GPS is about 1500
MHz and milliwatts.

Here are some links that might provide more information. The Coast
Guard site has pages on GPS, DGPS and eLORAN.

http://www.navcen.uscg.gov/eLoran/overview.htm

http://www.torkildsen.no/Navconf2007/Offermans.pdf

http://www.locusinc.com/pdf/Loran%20...0w%20logo6.pdf

http://www.locusinc.com/library/2005%20RTCM_Locus.pdf

http://www.askhelios.com/ERNP/docume...t%20300606.ppt

http://www.mycoordinates.org/satelli...uthnmyths1.php

http://www.popularmechanics.com/tech...y/4266972.html
 




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