War may effect wardrivers...

[blackwave]

In May 2000 President Clinton ordered that the intentional error in GPS signals be shut down (U.S. military GPS receivers could cancel the error). That stopped what Parkinson calls the "wiggle" in civilian GPS receivers, thereby making them far more accurate. Previously, automobile GPS units would often place a car up to two blocks from its actual location; today, GPS units are able to place a car on the correct side of a freeway.

The intentional error was meant to keep hostile powers from being able to use GPS to hit U.S. targets, but to Parkinson that never made sense. "I fought that wiggle at the highest levels from the start," he says, arguing that any enemy smart enough to use GPS guidance could also figure out how to cancel the error. "I'm glad to see it go."
http://www.discover.com/awards/02_aw...nications.html

... as most gpsers know this wiggle was removed... with the threat of possible war with iRAQ (and the talk of bio-weapons attached to gps units), do you think the US will reinstate the "wiggle"?

[murakami]

Selective availability (SA) will most likely not be enabled mainly because there are alternate GPS satellites (non US), widespread availability of commercial satellite imagery, military GPS signals are on a difference frequency, and its generally pointless. Contrary to popular belief, SA was first implemented in July of 1991 and not fully implemented until 1994, well after the Desert Storm.

Although unproven, there have been observations that the SA has been selectively turned on in several occasions since May of 2000

Interesting enough, the Gulf War probably was the major driver for the development of consumer GPS technology. There were a lot of surplus OD receivers available immediately after the Gulf War, and I suspect there were whole lot of chip orders that drove down the price.

[kampf]

I wonder if the "wiggle" would interfere with, or make inoperable, devices that have been marketed since that point.

Just think about the uproar from the soccer moms if they couldn't deliver their 2.5 kids to the soccer game with audible instructions from the GPS in their 6000lb Lincoln.

^the above story is ficticious, and it should be accurate enough to help them find a soccer field, but you get what i mean...

[blackwave]

Originally posted by kampf
I wonder if the "wiggle" would interfere with, or make inoperable, devices that have been marketed since that point.

I was watching the news (I know beat me)... and they were talking about iRAQ and it's bio-chemical drone missles now using GPS to guide them to their targets... then they talked about them getting onto US soil... then they brought up the plastic sheets and duct tape again... I had to turn it off... it made me wonder if the US would ever put the wiggle back, or just completely shut off its non-military gps satellites in the event of these drone things being detected during flight, or whatever.

[murakami]

Originally posted by kampf
I wonder if the "wiggle" would interfere with, or make inoperable, devices that have been marketed since that point.

of course it would, Selective Availability degrades the positional information.

WMDs are lot like horseshoes, close is good enough and a 300 meter error won't matter, you get more errors from incorrectly calculating position from different datums.

[FAWCR]

If you were watching this morning there was more fire added to this with:

http://www.canada.com/search/story.a...1-65a7f3593c47

Remember the T-shirt from DC10...."get noticed by Homeland Security" :-)

[TwinVega]

Originally posted by murakami
.....
WMDs are lot like horseshoes, close is good enough and a 300 meter error won't matter, ....

Like horseshoes? :D

[simple3]

I believe any error in SA can be overcome by using a slightly more expensive GPS with (Diferential) DGPS.

--simple3

[Stalker]

Originally posted by blackwave
I was watching the news (I know beat me)... and they were talking about iRAQ and it's bio-chemical drone missles now using GPS to guide them to their targets... then they talked about them getting onto US soil... then they brought up the plastic sheets and duct tape again... I had to turn it off... it made me wonder if the US would ever put the wiggle back, or just completely shut off its non-military gps satellites in the event of these drone things being detected during flight, or whatever.

I think they turned off the civilian GPS signal completely over afgahnistan while the US bombed them flat. There was some news articles about it so it must be true. Any info from someone who was there would be appreciated.

[blackwave]

yes, here is a similar article:
http://www.computerworld.com/mobilet...,65096,00.html

... though I am intersted to know if they would do this over US soil. i know the would do it if required - but what needs to reach that requirement?

[murakami]

Originally posted by blackwave
yes, here is a similar article:
http://www.computerworld.com/mobilet...,65096,00.html

... though I am intersted to know if they would do this over US soil. i know the would do it if required - but what needs to reach that requirement?

There are too many things dependent on commercial GPS frequencies: logistics, general aviation, even things like providing a time signal to earthquake monitoring stations use GPS. There really isn't a compelling usecase for turning on when we know that low or no tech terrorist actions can accomplish the same goals. Macveigh didn't need a GPS.

[astcell]

If the US tweaks the GPS readings, then why would the bad guys not just go on a White House tour and measure the false readings? Then input those to a warhead...the coordinates may be wrong but they'd match the final location. Now if the skew was constantly changing then that'd work I suppose.

[blackwave]

Originally posted by murakami
There are too many things dependent on commercial GPS frequencies: logistics, general aviation, even things like providing a time signal to earthquake monitoring stations use GPS. There really isn't a compelling usecase for turning on when we know that low or no tech terrorist actions can accomplish the same goals. Macveigh didn't need a GPS.

it is understood from past behavior that "terrorists" often find a cheap method to cause damage; the side effect being suicide for running into a building strapped with explosives... though with these public reports of these teched out drones being detected coming via ships and being assembled by terrorists already on US soil, what consideration is there that terrorists might take a different technological approach to attacking the US from within?... and finally what measures would the US do to protect its citizens if any. It is said these drones rely on GPS to reach their targets. Is this just going to be ignored as an "oh well, that is what collelateral damage is about"?... of course this is based from the premise of these public reports being true (which is plainly nonsensical as to why the US would allow these things to visibly be shipped into the US)... I find it interesting that if such needs were to be taken not only would the terrorists be hindered, but so would the citizens since you mentioned that GPS is obviously a shared resource for the daily infrastructure... and surely this must have been thought of before in some large thinktank... is it simply said that this information is being withheld so no counter measures are taken?... no need to answer any of these questions, it is all rhetoric anyway... feel free to comment though.

[murakami]

Originally posted by blackwave
it is understood from past behavior that "terrorists" often find a cheap method to cause damage; the side effect being suicide for running into a building strapped with explosives... though with these public reports of these teched out drones being detected coming via ships and being assembled by terrorists already on US soil, what consideration is there that terrorists might take a different technological approach to attacking the US from within?... and finally what measures would the US do to protect its citizens if any. It is said these drones rely on GPS to reach their targets. Is this just going to be ignored as an "oh well, that is what collelateral damage is about"?... of course this is based from the premise of these public reports being true (which is plainly nonsensical as to why the US would allow these things to visibly be shipped into the US)... I find it interesting that if such needs were to be taken not only would the terrorists be hindered, but so would the citizens since you mentioned that GPS is obviously a shared resource for the daily infrastructure... and surely this must have been thought of before in some large thinktank... is it simply said that this information is being withheld so no counter measures are taken?... no need to answer any of these questions, it is all rhetoric anyway... feel free to comment though.

You make an interesting point, but the history of the IRA shows that simple things work the best. Bringing and assembling drones then having them fly automatically to their target is technically possible, but execution would probably require a high degree of very sophisticated hands-on. Futhermore, there are other GPS constellations such as GLONASS that are also available. SA doesn't really help ammeliorate such an unlikely threat. It probably is more of hindrance.

In the unlikely occurence that GPS satellites get switched off or SA gets switched on, it is because there is very specific chatter. Kinda like the missile batteries around the Lincoln Memorial.

[MrYowler]

Simplicity...

I concur with the simplicity argument. Any idiot with a mortar mounted in the back of a pickup truck could probably bomb the hell out of the California State Capitol building, from about a mile away, in McKinley Park, for at least 15 minutes, or so, at nighttime, before authorities got wise to where the attack was coming from. It does not have to kill anyone, or hurt anyone, or even do any significant damage, to effectively shut down business in the State capitol, for probably a week or more, and cost an enormous amount of money while the State installs privacy-invasive countermeasures all over central Sacramento. The terror effect would be considerable, and the cost would be far greater, to defend against this type of attack, than the cost of implementing it - and this is the standard by which the success of guerrilla warfare is measured.

All of this, ignoring the devastating effect that the resulting countermeasures would have on the freedom and privacy of people who live and work in the Sacramento area, and throughout California; it's worth noting that it is the erosion of our way of life that the terrorists typically seek to achieve, and every time that we have one of these attacks, and the subsequent knee-jerk reaction, we give them exactly what they want, on a silver platter.

Finally, the would-be terrorist is within one block of a major freeway - so escape takes mere seconds, so long as the authorities have not yet arrived at the scene to determine what vehicle to chase. At a rate of one launch, every 15 seconds, for five minutes, the attacker could fire 20 mortar rounds into downtown, with ease - if he planned his attack, with this in mind, he could complete the attack in his allotted five minutes, and easily have ten minutes to disappear, while the authorities rounded themselves up to react. Here again, accuracy is not important, since damage to surrounding business infrastructure is just as effective in eliciting the desired reaction, as actually caving in the Capitol building dome. What the attacker really wants, is widespread effect, so as to make a large cross-section of people - preferably influential people, but anyone will do, in a pinch - feel unsafe. That buys him the knee-jerk response that the attacker is looking for...

An attack on the White House, or any other target, does not have to be successful, in order to have the desired result - it merely needs to give the public the perception that it *might have been* successful.

In terms relevant to the example given; there is no need to ship in, and assemble, a high-tech attack aircraft - every corner toy and hobby store sells radio-controlled planes for just a few hundred dollars. Strap your shit to one of these, and guide it in by radio - much more accurate, reliable, cheap, and logistically sound - and do you seriously think that anyone would have the slightest idea what you were doing, to stop you, before you achieved your goal? Sure, the FCC has equipment to track your transmitter - but they don't know which signal is yours, immediately, nor are the vans carrying the equipment likely to be deployed and manned, and close enough to find and stop you in time. Hell, by the time that they figure it all out, you've blown up your target and been gone for hours. You're riding the Amtrack to Vancouver, where you catch a bus into Canada, and fly to Europe from Ontario, changing planes to your destination in India. There, you have a car waiting to take you back to Iraq, via Jordan...

I just made that entire scenario up, on the spot, out of my head. Imagine how much better the plan is, that the real terrorist comes up with, having had weeks, months, or years to think about it, in advance... :-/

Simple works best...