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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. |
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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. |
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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 |
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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
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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
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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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