Disastrous GPS Jamming

 

Data Shows Disastrous GPS Jamming

Representatives of the GPS industry presented to members of the Federal Communications Commission clear, strong laboratory evidence of interference with the GPS signal by a proposed new broadcaster on January 19 of this year. The teleconference and subsequent written results of the testing apparently did not dissuade FCC International Bureau Chief Mindel De La Torre from authorizing Lightsquared to proceed with ancillary terrestrial component operations, installing up to 40,000 high-power transmitters close to the GPS frequency, across the United States. More at:

http://tinyurl.com/4u8zfn6

See also

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5ESS

Boy, does that take me back. I project managed the installation of those and cell towers back in the 90's when Sprint was growing their network.

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Tampa, FL - Garmin nüvi 660 (Software Ver 4.90), 2021.20 CN NA NT maps | Magellan Meridian Gold

Actually

UTC timing signals from the NIST-7 cesium clock in Boulder are broadcasts via radio station WWVB in Fort Collins, CO. The ultra-low 60KHZ transmissions can be received anywhere in North America.

An informative read for anyone interested: http://archive.coloradoan.com/article/20130311/NEWS01/303110...

As anyone involved in the telco industry knows, these timing signals have been the cornerstone for modern telephone engineering and design for decades.

GPS satellites are “self-timed” (GPST) and periodically synchronized with the Master Clock at the US Naval Observatory in Washington DC. GPST is not corrected to match the earth’s rotation (leap seconds are not added) and can be offset by as much as 16 seconds from terrestrial UTC.

The GPS time reference is

The GPS time reference is corrected and compensated through software. While leap seconds cannot be added (or subtracted) the time reference is kept by specification to at least one microsecond. However, according to the information in the link/article below, in practice, it is much more accurate: well within 40 nanoseconds of the UTC: USNO Master Clock. The NIST-F2 clock came on-line in April of this year. It is so accurate that it will neither gain nor lose a second in 300 million years. It was always amazing for me to think that this gizmo and the resulting time signal broadcast is what keeps the $20 "Atomic" Casio on our wrists accurate, for free, courtesy of the U.S. Government.

Here is a link explaining GPS time accuracy and the new NIST F-2 master clock:

http://www.nist.gov/pml/div688/nist-f2-atomic-clock-040314.c...

http://www.gpsinformation.net/main/gpstime.htm

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I was not aware of the

I was not aware of the recent conversion to the NIST-F2 clock standard. Thanks for the link.

The point of my post was simply to point out that GPST and UTC are different entities. Yes, there is a terrestrial synchronization and subsequent satellite upload that takes place to a very high degree of accuracy but the two are not equal.

Terrestrial time signal broadcasts such as WWVB have coverage limitations whereas The Global Positioning System is ideally suited to provide the entire planet with accurate time signals. If it were not for this fact, GPST and UTC would not have to match and the synchronization upload would not be necessary. As you pointed out though, the fact that UTC is provided by the GPS system is of great value to the public.

The GPS system, and to a lesser degree, the telecom industry do not care if it’s lunchtime, dinnertime or Miller time for that matter. It’s the time differential that makes these systems work. A common base point in time along with highly accurate incremental measurements are the key factors.

I realize this is a gross oversimplification of an extremely complex topic. I find the subject very interesting as it played a significant role in my working career. Thanks again for the information.

Before GPS - - - -

Box Car wrote:

What did they do before there were the GPS satellites? GPS has been available for civilian use for only about 20 years. Before that, highly accurate clocks were used throughout the network with each having to be synced on a regular basis to the NBS in either Washington (now closed) or Denver (Boulder). Oh, the 5E was the workhorse that brought digital to the subscriber. While it has been replaced with newer switches based on IP routing, the system and its outlying SLC-96's are still quite prevalent.

Before there was GPS, there was LORAN C. The clock I maintained would sync to either GPS or LORAN C. I lost the GPS antenna twice due to lightning (I guess) and the clock worked fine sync'd to LORAN C. It was in major alarm because it had lost one of it's references but the stability was within specs. The LORAN system has now been decommissioned, the powers that be have decided that GPS works fine and there is no longer a need for a terrestrial based navigation system.

Time and Nanoseconds

bdhsfz6 wrote:

I was not aware of the recent conversion to the NIST-F2 clock standard. Thanks for the link.

The point of my post was simply to point out that GPST and UTC are different entities. Yes, there is a terrestrial synchronization and subsequent satellite upload that takes place to a very high degree of accuracy but the two are not equal.

Terrestrial time signal broadcasts such as WWVB have coverage limitations whereas The Global Positioning System is ideally suited to provide the entire planet with accurate time signals. If it were not for this fact, GPST and UTC would not have to match and the synchronization upload would not be necessary. As you pointed out though, the fact that UTC is provided by the GPS system is of great value to the public.

The GPS system, and to a lesser degree, the telecom industry do not care if it’s lunchtime, dinnertime or Miller time for that matter. It’s the time differential that makes these systems work. A common base point in time along with highly accurate incremental measurements are the key factors.

I realize this is a gross oversimplification of an extremely complex topic. I find the subject very interesting as it played a significant role in my working career. Thanks again for the information.

Hi bdhsfz6!
You added to my knowledge here of these amazing clocks as well. Thank you! I think somewhere in those articles they talked about nanoseconds and what that meant as far as accuracy. +- 0.3 nanoseconds time error per day equals approx 1 second in 10 million years!! YIKES! Amazing! I also like the section where they mentioned that these new clocks now keep more accurate time than the earth itself.

I also think they improved the signal coming from Boulder in the last year or so. My venerable Heathkit CG-1000 "Most Accurate" clock struggled to receive that signal and update itself. (Three perfect frames must be received exactly one minute apart which is a tough standard when you're trying to receive a clean signal 1000+ miles away. The frames are stored and compared for this standard and if it is met, the microprocessor updates the display) Then there was a time a year or so ago when it didn't update for MONTHS. Presently though, the clock updates it's display almost everyday. I can tell because the the 10ths digit changes from dim to bright (this digit dims if the clock does not update itself at least once/day) and I frequently catch the "hi-spec" led illuminated. When this lamp is on, it indicates that the display is within 10 milliseconds of the WWV time. It will also adjust (trim) its internal time base oscilator to run more accurately than before. The more often it's updated, the better its accuracy during periods when the signal is to weak (or incomplete) to be used. Pretty sophisticated for the 1980's.

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"Primum Non Nocere" 2595LMT Clear Channel and Navteq Traffic

The Cornerstone of GPS

williston wrote:
bdhsfz6 wrote:

You added to my knowledge here of these amazing clocks as well. Thank you! I think somewhere in those articles they talked about nanoseconds and what that meant as far as accuracy. +- 0.3 nanoseconds time error per day equals approx 1 second in 10 million years!! YIKES! Amazing! I also like the section where they mentioned that these new clocks now keep more accurate time than the earth itself.

I also think they improved the signal coming from Boulder in the last year or so. My venerable Heathkit CG-1000 "Most Accurate" clock struggled to receive that signal and update itself. (Three perfect frames must be received exactly one minute apart which is a tough standard when you're trying to receive a clean signal 1000+ miles away.

It is amazing how technology has advanced time measurement to nanosecond accuracy. It is one of the factors that make the Global Positioning System work but is also one of the limiting factors in its position accuracy.

I was a big Heathkit fan back in the 80’s and actually owned a CG-1000. I never assembled the kit though and sold it on Ebay around 8 years ago. From your description of the unit, I should have kept it. Although outdated now, it’s still an interesting and useful product. Definitely ahead of its day for that era.

I used to receive WWV time signal broadcasts on my Ham rig in the 5 and 10 MHZ bands but I lost reception a few years ago for some reason. As you said, NIST has upgraded their broadcast antennas over the last 10 years but it hasn’t helped here where I live.

http://tf.nist.gov/stations/wwvh.htm

These days, I rely on my Fenix GPS watch for accurate time measurement. According to the link you provided, Garmin claims it deviates .5 to 1.5 seconds from UTC. That’s close enough for my needs.

Re: 5 and 10 mhz bands

It is very interesting that you should mention that. I have my GC-1000 locked on the 15 mhz band. The 5 and 10 mhz bands are too noisy and have been this way for quite some time now. The clock was built in 1984 and ran reliably until I re-built and upgraded the power supply on the clock in 2007, switching to an integrated switching regulator. This allowed the removal of the huge 5 watt resistor and the large heat sink tower on the the old power supply IC. It resulted in a huge heat reduction in the cabinet. The power supply produces virtually no heat now. I also replaced many of the vintage capacitors. The improvement was tremendous and the clock started updating itself almost every day. At some point (2010?) the signals seemed to vanish and with only occasional exceptions, it did not update for months until 8-10 months ago when it improved to the point that it now updates itself several times a day on the 15hz band.

Here is a link to the clock I built which uses the GPS signal to set itself and how it works.

http://www.amug.org/~jthomas/gpsii.html

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"Primum Non Nocere" 2595LMT Clear Channel and Navteq Traffic

Of Discipline and Clocks

(Warning: significant nerd content!)

The way most of these systems operate (from LORAN through to GPS, NTP, and a much older system) is more or less the same.

The device contains an oscillator, the more stable and predictable the better. An external reference is used to discipline the oscillator, giving it performance (stability) which approaches that of the external reference.

This configuration offers a lot of advantages, with two big ones. First, through disciplining, a less expensive oscillator can come close to the performance (stability) of the much more stable external reference. Second, once a history of oscillator performance relative to the standard is established, this history (of oscillator aging and drift) can be used to continue disciplining the oscillator should access to the external reference fail (this is known as holdover performance).

As an example, early telecoms towers used GPS to discipline a pretty good crystal oscillator to provide not only a time reference, but also a frequency reference for operating the gear. Not only does crystal + GPS meet some pretty impressive performance specs as to accuracy, using a good disciplining algorithm combined with history of the crystal oscillator, that performance can be guaranteed through a holdover period of some hours (12 to 24 for example) in the event the GPS signal isn't available (lighting strikes to the tower, car strikes to the tower, too much bird poo on the GPS antenna, and so on).

The next generation of telecoms gear used GPS to discipline a far better oscillator such as a rubidium oscillator. Such a package will give really tight performance with a holdover period of many days (at a tighter performance than a crystal box could achieve).

In a good computer system running code such as NTP, a similar process is used, comparing the performance of the computer system's clock to external references on a computer network (such as the internet). NTP checks the computer's clock against a number of external references periodically and applies different correction approaches to things like time of day (as it can't change the system's clock frequency). Type "ntpq -p" into the command line on your friendly local Linux, Unix, or Mac OSX system to see how your clock is doing.

Another example of an external reference disciplining a clock has been around far longer -- before electricity -- in pocket watches and then wrist watches. The external reference is the body temperature of the wearer, which maintains the timekeeping device at a relatively stable temperature, greatly improving its performance.

(There's also the fascinating story of clock synchronization required for nationwide TV networks, especially for color -- some amazing technology was needed, and developed.)

End of the nerd content -- if you're interested in more, look up "Time-Nuts"

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Apologies to the MODS

Hello Poi-factory MODS:
My apologies for running this string off the rails and turning it into a Nerd Convention about old musty Heathkit clocks and such. Starting to look like a spin-off of the "Big Bang Theory" here and it's my fault. Heathkit stuff is a sickness, what can I say except: "I apologize" and thanks for your continued patience. I guess a real liberal Judge would rule it's related to the original topic, but admittedly, only by a whisker! Judge Judy would surely just destroy me though. redface

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"Primum Non Nocere" 2595LMT Clear Channel and Navteq Traffic

while the kit discussion

williston wrote:

Hello Poi-factory MODS:
My apologies for running this string off the rails and turning it into a Nerd Convention about old musty Heathkit clocks and such. Starting to look like a spin-off of the "Big Bang Theory" here and it's my fault. Heathkit stuff is a sickness, what can I say except: "I apologize" and thanks for your continued patience. I guess a real liberal Judge would rule it's related to the original topic, but admittedly, only by a whisker! Judge Judy would surely just destroy me though. redface

could be debatable it was related to timing and the mistaken belief by some that GPS has been around forever.

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Always nice to "dust off" a topic/string started in 2011!

Box Car wrote:
williston wrote:

Hello Poi-factory MODS:
My apologies for running this string off the rails and turning it into a Nerd Convention about old musty Heathkit clocks and such. Starting to look like a spin-off of the "Big Bang Theory" here and it's my fault. Heathkit stuff is a sickness, what can I say except: "I apologize" and thanks for your continued patience. I guess a real liberal Judge would rule it's related to the original topic, but admittedly, only by a whisker! Judge Judy would surely just destroy me though. redface

could be debatable it was related to timing and the mistaken belief by some that GPS has been around forever.

I appreciate and thank you for your generosity in judgement here Boxcar! Thanks for the pass! wink

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"Primum Non Nocere" 2595LMT Clear Channel and Navteq Traffic

In regard to the effect of GPS Signals

FWIW, when reading the comments about how much of the country (and world) is strongly affected by GPS time signals, I was reminded of a novel that I recently read.

The book was "The Polaris Protocol" by Brad Taylor, and the core of the plot was the dependency of much of society upon the time signals from the GPS satellites. It falls into the "thriller" genre, and is worth a read if you care for that type of novel, even without an interest in GPS. If you have an interest in GPS systems and also enjoy "thrillers", it probably falls into the "must read" category.

- Tom -

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more BS from LightSquared

GPS Innovation Alliance Clips
July 12-18, 2014

In LightSquared news:
• The Wall Street Journal, Bloomberg, Inside GNSS and RCR Wireless all reported that Harbinger Capital Partners is suing the federal government for allegedly reneging on an agreement regarding LightSquared. The suit was filed Friday, July 11 with the U.S. Court of Federal Claims. “By requiring Harbinger to accommodate the GPS industry’s continued unlawful occupation and use of LightSquared’s L-band spectrum,” Harbinger said, “the United States effectively reallocated LightSquared’s spectrum to the GPS industry.”
• DealBreaker posted a tongue-in-cheek item about the lawsuit, noting that in the last 11 months, Philip Falcone has sued Dish founder Charlie Ergen twice, the GPS industry, and now the U.S. government. The article reads in part, "Who is next? Clearly, it could be anyone."
• The Wall Street Journal, Reuters, Bloomberg, Denver Business Journal and Law360 all reported that LightSquared reached a deal on a restructuring plan that has the support of Charlie Ergen, its top secured lender. In a hearing Monday, a lawyer for a special committee of LightSquared's board said the new plan would give Mr. Ergen a $1 billion allowed claim in the bankruptcy case, and calls for him to invest $300 million in new money into the company. Multiple outlets quoted David Friedman, a lawyer for Harbinger, who called the development "a stunning reversal," and expressed concerns about whether the plan would try to limit the lawsuit Harbinger filed against the federal government.
• Writing on his blog, Tim Farrar commented that Philip Falcone's recent actions "basically destroy prospects of further progress with the FCC," noting that his lawsuit with the U.S. government "is expected to freeze further contacts with the FCC.” Farrar asserted that a "likely" next step is for LightSquared to sue Harbinger to prevent the lawsuit from moving forward.

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CG-1000

I own one of these CG-1000s, even wrote a review of the assembly process. The unit is in storage, along with my first computer.

Did you get the R-232 interface option for yours?

I found it just as easy to connect with WWVB in Boulder as it was with WWVH in Hawaii (but then, I'm on the west coast, too).

Homebrewed antenna was junk, reception picked up tremendously once I hooked it to the TV cable. There may have been propagation delays from hooking it to the cable, I don't know.

The absolute oddest thing I ever heard from WWVB was after the regular 'top of the hour' information (like North Atlantic Weather, and the geomagnetic report, etc.); at the end of the regular broadcast, I heard "Umbrella... repeat, umbrella". Gotta wonder what THAT was for!

We should probably take this to PM...

Very Interesting Issue...

Thanks for sharing.

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