Re: M_Boats: Check out Coalition to Save Our GPS
i too have been following this issue for the last year-ish. a good friend, and college roommate, has a PhD in this stuff (some of his designs have been put into orbit). i have been asking him his opinion on the LightSquared situation. here is his point of view (POV) on the latest that has been discussed here on the Mboat listproc - -- begin a PhD's POV -- Well, what has been said is mostly not true. (except "go sailing with no worries") [note: my friend is also a life-long sailor. - dave] GPS jamming is really easy. The signals are "Sub Thermal" meaning that they are really, really , really weak. Spread spectrum does help with interference, and the next generation of satellites *may* be more powerful, but that is not what I heard. I thought Light Squared said that the next generation of *receivers* may be more resistant to interference. So everyone should just replace their equipment so they can use a crappy radio system. Personally, I think the DoD, FAA, and FCC is going to tell LightSquared to go stuff it. On the other hand, I just read some articles and the authors could be confused. This could be a test about if business controls government, in which case we are screwed. -- end PhD POV -- i look forward to reading other's opinions ... i still use paper charts and dead reckoning as my #1 and #2 navigation tools. GPS is a helplful #3. i'm not a fan of digital charts (chart plotters). i do like the speed over ground feature on a GPS - much better than putting a thru-hull on the boat. :: Dave Scobie --- On Wed, 2/1/12, robbin roddewig <robbin.roddewig@verizon.net> wrote:
Hi Gary, this "threat" from light squared has been a topic for quite a while. When you look at the technical details it is very benign. GPS is inherently immune to a high level of interference due to the spread spectrum nature of the signal (processing gain of 1000 or 30dB). You can always hypothesize a situation where you could jam even a highly resistant system like GPS but these situations tend to be very pathological. The next block of GPS that is under development is even more resistant to interference, as it is targeted for use by commercial airliners. There is not a great understanding of GPS (or Assisted GPS, reference the erroneous statements in the latest practical sailor article on Nav apps) but bottom line is that I would not worry too much about GPS being compromised. Go sailing with no worries!
Robbin
On 2/1/2012 12:14 AM, GILASAILR@aol.com wrote:
_Click here: Coalition to Save Our GPS_ (http://saveourgps.org/)
Conflicting use/frequencies may have an effect on the viability of GPS in the near future - see link for more info.
From "Scuttlebutt".
GO
David, I understand your friend's opinion. I have been designing GPS systems and devices for about 6 years, I teach the subject in grad school as part of a couple of my courses so I am not shooting from the hip, but my opinion is just my opinion. There is a lot of disagreement about the possibility of jamming due to other users like light squared. I hope we never have to care. Robbin On 2/1/2012 11:47 AM, W David Scobie wrote:
i too have been following this issue for the last year-ish.
a good friend, and college roommate, has a PhD in this stuff (some of his designs have been put into orbit). i have been asking him his opinion on the LightSquared situation. here is his point of view (POV) on the latest that has been discussed here on the Mboat listproc -
-- begin a PhD's POV --
Well, what has been said is mostly not true. (except "go sailing with no worries") [note: my friend is also a life-long sailor. - dave]
GPS jamming is really easy. The signals are "Sub Thermal" meaning that they are really, really , really weak. Spread spectrum does help with interference, and the next generation of satellites *may* be more powerful, but that is not what I heard. I thought Light Squared said that the next generation of *receivers* may be more resistant to interference. So everyone should just replace their equipment so they can use a crappy radio system.
Personally, I think the DoD, FAA, and FCC is going to tell LightSquared to go stuff it.
On the other hand, I just read some articles and the authors could be confused.
This could be a test about if business controls government, in which case we are screwed.
-- end PhD POV --
i look forward to reading other's opinions ... i still use paper charts and dead reckoning as my #1 and #2 navigation tools. GPS is a helplful #3. i'm not a fan of digital charts (chart plotters). i do like the speed over ground feature on a GPS - much better than putting a thru-hull on the boat.
:: Dave Scobie
--- On Wed, 2/1/12, robbin roddewig<robbin.roddewig@verizon.net> wrote:
Hi Gary, this "threat" from light squared has been a topic for quite a while. When you look at the technical details it is very benign. GPS is inherently immune to a high level of interference due to the spread spectrum nature of the signal (processing gain of 1000 or 30dB). You can always hypothesize a situation where you could jam even a highly resistant system like GPS but these situations tend to be very pathological. The next block of GPS that is under development is even more resistant to interference, as it is targeted for use by commercial airliners. There is not a great understanding of GPS (or Assisted GPS, reference the erroneous statements in the latest practical sailor article on Nav apps) but bottom line is that I would not worry too much about GPS being compromised. Go sailing with no worries!
Robbin
On 2/1/2012 12:14 AM, GILASAILR@aol.com wrote:
_Click here: Coalition to Save Our GPS_ (http://saveourgps.org/)
Conflicting use/frequencies may have an effect on the viability of GPS in the near future - see link for more info.
From "Scuttlebutt". GO
My qualifications to speak on this subject come from working in the land surveying business for the past 15 years. All of us in land surveying who depend on GPS for our livelihood are very concerned. If Lightsquared gets approved GPS will go down in a wide area around their transmission towers. A test was recently done on their proposal in Nevada and it totally obliterated the GPS signal. No position information could be obtained anywhere near the test area. LightSquared's proposal that everybody purchase new equipment that filters out their signal is ridiculous. They need to find a frequency that is not adjacent to GPS or shelve their plan because it is incompatible with current civil use of GPS. This opinion is not from a PHD but from a real world GPS user. More information from the pros below and a link to a website with further info. Statement by the National Executive Committee for Space-Based Positioning, Navigation, and Timing December 14, 2011 WASHINGTON -- Today, a government technical group reviewed the findings from last month's testing of LightSquared's proposal to provide new broadband service. The final test report will be sent to the National Telecommunications and Information Administration (NTIA), which advises the President on telecommunications policy, and represents federal agencies to the Federal Communications Commission (FCC). Preliminary analysis of the test findings found no significant interference with cellular phones. However, the testing did show that LightSquared signals caused harmful interference to the majority of other tested general purpose GPS receivers. Separate analysis by the Federal Aviation Administration also found interference with a flight safety system designed to warn pilots of approaching terrain. The findings were presented to the technical steering group which represents the nine federal agencies that make up the National Executive Committee for Space-Based Positioning, Navigation, and Timing. Over the next several weeks, the final analysis of the findings will be completed and a final report will be transmitted from NTIA to the FCC. http://www.gps.gov/news/2011/12/lightsquared/ -----Original Message----- From: montgomery_boats-bounces@mailman.xmission.com [mailto:montgomery_boats-bounces@mailman.xmission.com] On Behalf Of W David Scobie Sent: Wednesday, February 01, 2012 8:48 AM To: For and about Montgomery Sailboats Subject: Re: M_Boats: Check out Coalition to Save Our GPS i too have been following this issue for the last year-ish. a good friend, and college roommate, has a PhD in this stuff (some of his designs have been put into orbit). i have been asking him his opinion on the LightSquared situation. here is his point of view (POV) on the latest that has been discussed here on the Mboat listproc - -- begin a PhD's POV -- Well, what has been said is mostly not true. (except "go sailing with no worries") [note: my friend is also a life-long sailor. - dave] GPS jamming is really easy. The signals are "Sub Thermal" meaning that they are really, really , really weak. Spread spectrum does help with interference, and the next generation of satellites *may* be more powerful, but that is not what I heard. I thought Light Squared said that the next generation of *receivers* may be more resistant to interference. So everyone should just replace their equipment so they can use a crappy radio system. Personally, I think the DoD, FAA, and FCC is going to tell LightSquared to go stuff it. On the other hand, I just read some articles and the authors could be confused. This could be a test about if business controls government, in which case we are screwed. -- end PhD POV -- i look forward to reading other's opinions ... i still use paper charts and dead reckoning as my #1 and #2 navigation tools. GPS is a helplful #3. i'm not a fan of digital charts (chart plotters). i do like the speed over ground feature on a GPS - much better than putting a thru-hull on the boat. :: Dave Scobie --- On Wed, 2/1/12, robbin roddewig <robbin.roddewig@verizon.net> wrote:
Hi Gary, this "threat" from light squared has been a topic for quite a while. When you look at the technical details it is very benign. GPS is inherently immune to a high level of interference due to the spread spectrum nature of the signal (processing gain of 1000 or 30dB). You can always hypothesize a situation where you could jam even a highly resistant system like GPS but these situations tend to be very pathological. The next block of GPS that is under development is even more resistant to interference, as it is targeted for use by commercial airliners. There is not a great understanding of GPS (or Assisted GPS, reference the erroneous statements in the latest practical sailor article on Nav apps) but bottom line is that I would not worry too much about GPS being compromised. Go sailing with no worries!
Robbin
On 2/1/2012 12:14 AM, GILASAILR@aol.com wrote:
_Click here: Coalition to Save Our GPS_ (http://saveourgps.org/)
Conflicting use/frequencies may have an effect on the viability of GPS in the near future - see link for more info.
From "Scuttlebutt".
GO
Mark, good info, and between this and SOPA Washington is on a Track to screw up both GPS and the Internet as we know it. Crazy isn't it? Sent from my iPad On Feb 2, 2012, at 4:04 PM, "Roberta Dvorscak" <edarts93@earthlink.net> wrote:
My qualifications to speak on this subject come from working in the land surveying business for the past 15 years. All of us in land surveying who depend on GPS for our livelihood are very concerned. If Lightsquared gets approved GPS will go down in a wide area around their transmission towers. A test was recently done on their proposal in Nevada and it totally obliterated the GPS signal. No position information could be obtained anywhere near the test area. LightSquared's proposal that everybody purchase new equipment that filters out their signal is ridiculous. They need to find a frequency that is not adjacent to GPS or shelve their plan because it is incompatible with current civil use of GPS. This opinion is not from a PHD but from a real world GPS user. More information from the pros below and a link to a website with further info.
Statement by the National Executive Committee for Space-Based Positioning, Navigation, and Timing
December 14, 2011 WASHINGTON -- Today, a government technical group reviewed the findings from last month's testing of LightSquared's proposal to provide new broadband service. The final test report will be sent to the National Telecommunications and Information Administration (NTIA), which advises the President on telecommunications policy, and represents federal agencies to the Federal Communications Commission (FCC).
Preliminary analysis of the test findings found no significant interference with cellular phones. However, the testing did show that LightSquared signals caused harmful interference to the majority of other tested general
From Charles Brennan on the Trailer Sailor Bulletin Board:
http://www.wirelessweek.com/News/2012/02/Policy-and-Industry-LightSquared-Ba cker-Rebuts-Grassley-Bribery-Charges-Legal/?et_cid=2458531&et_rid=54130714 Now they're having to deny charges that they attempted to bribe a United States Senator. And they picked the wrong one to bribe; not because he's particularly immune to such attentions, but because he doesn't even understand the situation. (From the article: ) "Grassley is a vocal critic of LightSquared's plans and has been after the FCC to answer questions about why it granted LightSquared a waiver for its service over the concerns of the NTIA and GPS industry." Uhh . . . . . they didn't. "The waiver blocks LightSquared from deploying its network until it addresses problems with GPS interference. The company has struggled to come up with a fix for the issue and has yet to be given permission to launch." And Bold As Brass and twice as Brazen, to the very end: "In it, a Harbinger representative called Grassley's charges "unsubstantiated," claimed there was nothing inappropriate about contact between the hedge fund and the senator's office and charged that Grassley's staff contacted the media about the allegations without giving Harbinger a chance to defend itself first." Nothing inappropriate about contact between the hedge fund and the senator's office huh? ON WHAT PLANET!!???!??? I don't blame Grassley's staff one bit for their actions. (Just wish they'd spend a little more time explaining to their boss, what is actually going on.) I felt last year at this same time, that the FCC had been unusually open-minded and fair about appealing to both sides of the issue, saying in effect: "You can give it a shot using your own money if ya want; but you ain't getting a waiver until you promise it ain't gonna hurt nothin' else that depends on those bands." And here is a historical example of why I felt that this was a forward-looking approach: The time is World War Twice. Allies are gearing up to fly aircraft across the Atlantic with vital war materials. They train the navigators to use octants to take the absolute shortest route possible. The Learned Aeronautical Engineers come up with these horrendously complicated fuel/load/RPM/Airspeed tables. The pilots have to fly the planes perilously close to a stall speed in order to save enough fuel to make it clear across the Atlantic in their DC-2's. That means considerable yoke forces on the controls, so both pilot and co-pilot have to strain away at that thing. (Taking turns massaging out the arm and shoulder cramps.) The trip takes most of a day and the planes land with minimal fuel aboard. They have to wait until the following day to start back. Rough, Brutal, Backbreaking, Tension-Laden work. Not all the planes make it across. Some of the Pilots questioned the calculations of the Engineers. Finally, during one of the trips, a Navigator made a fatal error in his calculations and everyone aboard realized there was too little fuel and too many miles in front of them and they were facing their imminent demise at some as yet unknown spot in the Atlantic ocean. The pilots decided: "The Hell with it!" and moved the throttles to a more normal flying position, perhaps figuring: Why delay the Inevitable? To everyone's astonishment, they made it. Ahead of all the other planes that had left at the same time, oh, by the way. The now-angry pilots all demanded an explanation from the Engineers. "Of course!" The Engineers exclaimed. You go faster and use more fuel up in the first half of the flight, you can travel more efficiently in the second half of the flight. They whipped out their slide rules and the next morning had brand new tables for the pilots to use. Now that the original flight syllabus had been thrown out the window, they could make the flights in half the time, they could return the same day they left, which allowed for daily trips with material and with far less wear and tear on flight crews and yes, Virginia, we won the War. The thing I always took from that bit of History is that the Experts ain't always the Experts. Everything they calculated was correct, but they didn't take into account alternative ways of looking at the problem. Turns out one of the alternative ways of looking at the problem was wayyyyyyyyyyyyy safer and more efficient. This is why, when LightSquared made their audacious proposal in the face of an entire industry saying: "It'll never work." I thought back to those practical pilots, facing all those Learned Engineers. What if LightSquared figured out a new way to do things that nobody ever did, before? Mark Twain once said: "An Englishman is a person who does things because they have been done before. An American is a person who does things because they haven't been done before." Even though I know (barely!) enough about microwave propagation, to know that was one hell of a steep uphill road to climb, I was half-way rooting for the scrappy upstart to figure out something, all the rest of us had missed. I was also surprised at the egalitarian approach of the FCC to permit just that, without actually giving away anything. As we've seen since: God Does Not Repeal The Laws Of Physics For Anybody. And my mild disappointment at LightSquared's initial (to be honest: their completely predictable) failures, has since turned into Contempt and Rage, since they're no longer trying for technical solutions to the problem, but increasingly bizarre legal challenges. And apparently, now skirting the line of ILLEGAL solutions. The Italians have a word for this: Basta. (Enough.) Basta, LightSquared. One guy's musings, Charles Brennan
-----Original Message----- From: montgomery_boats-bounces@mailman.xmission.com [mailto:montgomery_boats-bounces@mailman.xmission.com] On Behalf Of Neil Dorf Sent: Thursday, February 02, 2012 8:17 PM To: For and about Montgomery Sailboats Subject: Re: M_Boats: Check out Coalition to Save Our GPS
Mark, good info, and between this and SOPA Washington is on a Track to screw up both GPS and the Internet as we know it.
Crazy isn't it?
Sent from my iPad
On Feb 2, 2012, at 4:04 PM, "Roberta Dvorscak" <edarts93@earthlink.net> wrote:
My qualifications to speak on this subject come from working in the land surveying business for the past 15 years. All of us in land surveying who depend on GPS for our livelihood are very concerned. If Lightsquared gets approved GPS will go down in a wide area around their transmission towers. A test was recently done on their proposal in Nevada and it totally obliterated the GPS signal. No position information could be obtained anywhere near the test area. LightSquared's proposal that everybody purchase new equipment that filters out their signal is ridiculous. They need to find a frequency that is not adjacent to GPS or shelve their plan because it is incompatible with current civil use of GPS. This opinion is not from a PHD but from a real world GPS user. More information from the pros below and a link to a website with further info.
Statement by the National Executive Committee for Space-Based Positioning, Navigation, and Timing
December 14, 2011 WASHINGTON -- Today, a government technical group reviewed the findings from last month's testing of LightSquared's proposal to provide new broadband service. The final test report will be sent to the National Telecommunications and Information Administration (NTIA), which advises the President on telecommunications policy, and represents federal agencies to the Federal Communications Commission (FCC).
Preliminary analysis of the test findings found no significant interference with cellular phones. However, the testing did show that LightSquared signals caused harmful interference to the majority of other tested general
participants (5)
-
Neil Dorf -
robbin roddewig -
Roberta Dvorscak -
Tod -
W David Scobie