GPS signals are surprisingly easy to disrupt
economist.com
economist.com
However, it is highly doubtful this was done by a delivery driver. There is no point in jamming the signal for 10 minutes. What could it accomplish? If the purpose is to take an illegal detour (going against a one way street) the company has logs of all your trips and will soon figure why you have a 10 minute gap everyday.
The article states "timestamps on trades made in financial institutions can be affected" There's your likely culprit; someone who for whatever reason needs to affect timestamps.
Remember, though, that the time a trade occurred (at the sub-millisecond level) might well mean thousands of dollars (or more).
Might as well be anyone who'd rather not be tracked if they can help it. I can imagine perhaps a VIP or even an organized crime member who prefers their car free of GPS trackers when they drive around town visiting associates.
If your employer doesn't allow legally required breaks you can use the GPS log in your suit against the company. Otherwise it sounds like you weren't doing your job.
Sounds a bit harsh to me.
What a horrible example. They actually get up and walk around probably dozens of times per day. That is completely different from long-haul trucking, where you may only get 2 stretch breaks in a 10 hour period.
Then one day the entire plant and all the workers have been replaced with a few industrial robots.
His problem is he loves the being a doctor part but hates the ever increasing paper work.
Let's take the job of a bus driver in a major city, which I did for a year. Everyone is out to get you. People try to stop short in front of you so you'll hit them and they'll collect insurance or they're trying to commit suicide. Drivers always try to get around you and beat you causing dangerous conditions. Passengers complain constantly and look for reasons to sue. Passengers get sick and throw up on your bus. Management sets impossible standards, so if for example you are late due to traffic it's too bad if you need to pee at the end of one trip (where you normally get a 10 minute layover to smoke and pee) because they make you turn right around and catch up. City monitors ride the bus to evaluate everything you do. Company monitors do the same. Passengers call the company and complain if they dont' like you. Cameras are on all the time in the bus and you will get called in and questioned about anything that happened on your shift. City police won't hesitate to write you a traffic ticket. You can have two "incidents" a year before you are fired. It was the hardest job I ever did, but the most rewarding because I made the grade and didn't wash out, and on a good trip (once around) it was very Zen being the calm meditative driver (which is state the job forces you into) All for 12 dollars an hour.
> it was very Zen being the calm meditative driver
My brother is a long-distance driver, and while on a short vacation (I'm a programmer) I took the chance of accompanying him in one of his job trips. While you sit in the right-sit as a passenger everything seems nice and beautiful, but then you notice the driver's stress of not making it in time, or how he just tries to "trick" the system "just that little" so that he'd make to the destination without exceeding the allowed gas limit, and lots of things like that. For comparison us programmers have it relatively easy.
I think everyone should work jobs like these, something different, to give a better perspective on life and exit the echo-chamber for a while :)
Of course, it will depress a lot of us who have grown up expecting to be treated like royalty due to our skills. Thankfully, if you're a great (top 1%) salesperson, you can still get that, but it takes a tonne of hard work to get there!
[1] http://www.threefeloniesaday.com/Youtoo/tabid/86/Default.asp...
Take the first example on the page you linked to, where he claims a woman was sentenced to two years in prison for cluelessly buying lobsters in plastic bags taht should have been packed in boxes. Bullshit: she was sentenced for conspiracy, mislabeling of produce, and violations of the Lacey act for illegal harvesting of underage/undersize lobster, in defiance of Honduran laws designed to preserve their fisheries, over a 5 year period. The feds didn't set out to prosecute Huang; they were approached by Honduan authorities and asked for help in stopping the illegal fishing activities. See https://bulk.resource.org/courts.gov/c/F3/331/331.F3d.1228.0... for the appeal court judgment - and ask yourself why Silverglate doesn't provide his readers with a link to the judgment or even an accurate summary of the indictment.
Every single case I have ever seen Silverglate cite involves a similar level of misrepresentation on his part.
Here's what Harvey wrote about prosecutorial misconduct in Aaron Swartz's case, for instance: http://dankennedy.net/2013/01/24/the-swartz-suicide-and-the-...
I'm not sure what <anigbrowl> has against Harvey, but it seems like a personal vendetta untethered to reality.
Here's what Harvey wrote about prosecutorial misconduct in Aaron Swartz's case, for instance: http://dankennedy.net/2013/01/24/the-swartz-suicide-and-the-...
I'm not sure what <anigbrowl> has against Harvey, but it seems like a personal vendetta untethered to reality.
At the end of the day, route optimisation can make or break a courier company, and getting good metrics on driver routes is just as important as getting (for example) tracebacks on your errors when coding.
The smart companies will take a no-blame approach: a driver is responsible for his route with the assistance of the intelligence provided by the company. Any follow-up should be constructive, and the good drivers will feed information back to improve the system.
There is no way it should be used to check your break schedule, and any operations manager should be coming down like a ton of bricks on anyone who is undermining such an important tool in their business.
http://www.economist.com/node/18304246
That article was inspired by a trucker who drove by Newark Airport every day, disrupting GPS service there.
GPS signals come from satellites. AFAIK there are about 20-40 GPS satellites. Let's say each covers at least 1/50 of the Earth's surface area, about 500 million km^2. That's 10 million km^2 per satellite.
What's the max power generation you can fit on reasonable-sized satellite that's going to be in orbit for decades? I'm guessing not more than 10 kW. So 10 kW / 10 million km^2 means you have .001 watt per km^2.
GPS signals being easy to jam isn't surprising. What's surprising is that you can detect them with equipment that's small and cheap enough to fit in a cellphone!
An interesting consequence of this is that you don't need a very fancy receiver, hardware-wise, because your software already has to be extremely sophisticated. For example, you can use a 1-bit ADC rather than trying to be more sophisticated about exactly how strong the signal is at any given moment.
The ability for GPS to (sometimes) work indoors these days is indeed pretty crazy. The signals are already incredibly weak, and you'd think having a roof and walls and pipes and wiring in the way would make it impossible to read them.
I'm excited for the new GPS satellites, GPS works well already but with modern technology in the satellites it should be much better.
I haven't been able to find any more recent info about the incident.
US military systems are inertially guided only accepting GPS corrections within the error bounds of their extraordinarily tight inertial measurements. If the GPS is outside the error bounds, it is presumed to be compromised. There is no such thing as an intrinsically GPS-guided weapon; they are always inertially guided with GPS corrections. Modern US inertial systems are similar to GPS in terms of precision so GPS is increasingly superfluous.
As a consequence, the US military has never been significantly vulnerable to loss of GPS. Their systems were designed, from Soviet days, to assume that GPS could be compromised or lost since the Soviets had that ability. Knock out GPS and you still have to deal with ultra-precise solid-state optical gyros.
Many commercial systems take a cheap shortcut and rely on GPS but, contrary to popular mythology, US military systems never have.
For deep alpha signals, a millisecond is pretty negligible (especially when you are calculating minute or 10 minute bars).
For microstructure trading strategies, since the timing doesn't manipulate the book (which is where most microstructure trades derive alpha from), the effect is similarly negligible.
And for cross-exchange and cross-asset arbitrage, where microseconds may seem matter (regnms), slight drifts are permissible insofar as you can plausibly argue that even if the clock is slightly off, your view of the market is internally consistent
Umm.. the article mentions that NK has been jamming GPS, and Iran allegedly landed US drone via GPS hacking.
Well resourced attackers are doing it.
The MMO company had a issue with their own physical logistics, and had to put their login server across the street in another building.
They put special antennas between the two buildings, to keep the thing running, and it worked great, until one day, it didn't.
After a while trying to figure what was going on, they noticed that a huge delivery truck parked illegally (the place where it parked was illegal to anyone park), and the place he choose made the bulk of the truck metal stay right between the two antennas...
EDIT: Also when internet was still dial-up, one delivery truck ignoring height limits managed to cut all phone cables near my town biggest ISP, leaving the entire city without internet. I did not appreciated it...
That, coupled with license plate scanners at those locations, ought to find the culprit.
(And then they can launch an armed drone to take him/her out...)
(I suppose one could program a missile to follow the light...)
basically shining a very bright light
But they're far away. Really really far away, to the tune of 21,000km. (The Earth is about 12,000km wide.)
By the time the signal makes it to the surface of the planet, the inverse square law has punched it down to -130 dBi, which is well below the thermal noise floor of room temp electronics. GPS receivers pull a useful signal out of a storm of random noise using deep information theory magic, which is vulnerable to several clever low power attacks.
Even a dumb jammer doesn't need much power, though.
one could program a missile to follow the light...
"The AGM-88 High-speed Anti-Radiation Missile (HARM) is a tactical, air-to-surface missile designed to home in on electronic transmissions coming from surface-to-air radar systems."
Any keywords I can look up as to how this is done?
Basically, even though the signal is below the noise floor, part of the signal is the output of a pseudo-random number generator with known properties, so by setting up your own PRN, and then trying different (time) alignments, the correct alignment will stick out, despite the noise (which all averages out). Once you have the time alignment, you can read the rest of the signal, and then you can tell how far you are from that satellite ((it's clock - your clock) / c). Repeat for other satellites and you're done.
Can't find any good references, but that's what our information theory lecturer said! Also, it explains why a hot start is quicker than a cold start (if you know where you are, and the accurate time, you know what alignments to try to start looking for the satellite signals.)
http://servv89pn0aj.sn.sourcedns.com/~gbpprorg/mil/gps4/GPS-...
Ultimiately, the lack of MAC and encryption makes civilian GPS MITMable.
(Discliaimer: I worked at Trimble.)
We initially used an expensive spectrum analyser attached to a spare LNB (pointed at the parking area) but that needed you to notice the noise. So I used a USB enabled RF power meter interfaced to Excel (so sue me, it was a rush job and we weren't equipped for development). A script ran which fetched values, when there was a spike in received power it played an alarm and flashed the screen.
The next step was to ask security to hold anyone in the carpark while a large angry engineer went to give the courier a piece of his mind. It worked, courier companies were informed, people were shouted at and I believe it stopped.
There are probably better ways of doing this, but it was effective and built from spare parts.
This is in the UK, so it's probably OFCOM who do the regulation and prosecution. (http://stakeholders.ofcom.org.uk/enforcement/spectrum-enforc...)
EDIT: Whoops, yes, this is mentioned in the article.
Hmm, yes kind of like how a new GPS costs $5K, because the first .mil model did cost that much. Or all computers currently cost millions of dollars because the first ones did.
For a price, one could acquire the necessary hardware/software to mitigate Selective Availability in order to increase the accuracy of GPS readings, although I forget what those prices were/are.
The US claim that since 2008 they've been launching GPS satellites without selective availability capabilities.
That means 27 of the current working GPS satellites are older ones which do have SA which could be switched back on at any time, and 12 are newer allegedly non-SA equipped satellites.
They didn't permanently switch off Selective Availability til mid 2000, but they could and did temporarily switch it off when it suited them (and, no doubt, could easily switch it back on today if they thought it worthwhile… They claim any satellites launched since 2008 haven't had SA capability, but I suspect that's only a small-ish percentage of the GPS constellation today…)
Their price isn't so much the hardware itself, in fact, most of the receivers seen in cell phones today cost less than $1USD. However, when dealing with more accurate receivers, the receivers typically need extensive calibration and testing. I mean, it's possible to get measurements from GPS accurate to 1mm, but you need to have both a careful setup and very good knowledge about the errors associated with your receiver. So yeah, these receivers are actually quite expensive, and most of it is because the calibration on repeatability and stability of these sensors is of the utmost importance.
On a secondary note, survey-grade receivers are typically not as prone to jamming as consumer-grade receivers, mostly because they can use multiple GPS frequencies / can collect over a wider bandwidth. There's a lot more to it than that, but effectively the point I'm making is that the receivers spoken of in the article are not the same as everyday GPS receivers.
If you want to see how crazy the prices on these receivers can get, look no further than http://www.surveyorsmart.com/product.sc?productId=548. I doubt many surveyors would go for that particular model by Leica, as it is definitely expensive, even for survey equipment standards, but it's not unreal in terms of pricing.
the trick is to use the carrier itself, which is higher frequency than the signal modulated on it. also, relative offsets are easier that absolutes (removes many systematic errors).
i wrote (the software for part of) one of these (not for leica, for some geophysical survey company) back in the day (although it was not mm resolution!)
Having said that, I wonder what the magnitude of ionospheric changes have on the phase difference of the carrier signals from satellites in different directions?
(Even though I know how it works, the idea of getting millimeter precision in measuring distances to something that's at least 20,000km away and traveling at almost 4km/sec seems like very black magic to me… Surely that can't actually _work_ in practice…)
The problem of working out which of the peak/troughs in the carrier wave you're in almost certainly requires terrestrial DGPS assistance (http://en.wikipedia.org/wiki/Differential_GPS). If you can use that to get ~100mm precision - that allows you to use the phase difference in the 200mm wave length to get sub mm measurements.
Like I said, I understand how it works – I just find it hard to believe it's actually practically possible… Deep magic…
They used to (ca. 2000) get ~1mm accuracy in the plane of the Earth, and ~1cm accuracy in the radial direction. The accuracy seems to have increased in the meantime, and it appears to be ~0.1mm in the plane of the Earth.
GPS is combined with other sensors like strain meters, etc., into something called Plate Boundary Observatory: http://pbo.unavco.org/instruments/gps
http://www.topconpositioning.com/products/total-stations/con...
"can measure in reflectorless mode up to 500m at an incredible 3mm + 2ppm accuracy."
A typical GPS:
http://www.topconpositioning.com/products/gps/modular-soluti...
Static H: 3mm +0.5ppm (x baseline length) V: 4mm +1.0ppm (x baseline length)
So GPS gives you lower PPM than optical for long runs but lower accuracy on short runs.
You could probably take multiple measurements and play triangulation games to get the error to, or under, one mm given enough time effort and money.
The best I've seen in consumer space so far is (surprisingly) the iPhone 5. Full AGPS and GLONASS support, which is better than most Android phones.
Ultimately, I don't know if I can give you explicit advice on the matter, but I would suggest you search for some way to integrate something such as an IMU into your navigation system, if possible. A properly implemented dead reckoning plus GPS is usually pretty hard to fool, as one of the systems will drop errors as soon as something starts to go wrong. However, getting the proper integration might cost you more than you're willing to pay, so it may just be in poor taste for me to even bring it up.
What we should be doing is replacing $1 GPS receive chipsets in phones with procession positions chipsets, and taking advantage of CORS reference stations (http://geodesy.noaa.gov/CORS/) for sub-centimeter positioning.