Posted on 09/19/2007 12:08:05 AM PDT by anymouse
Today, the President accepted the recommendation of the Department of Defense to end procurement of Global Positioning System (GPS) satellites that have the capability to intentionally degrade the accuracy of civil signals. This decision reflects the United States strong commitment to users of GPS that this free global utility can be counted on to support peaceful civil activities around the world.
This degradation capability, known as Selective Availability (SA), will no longer be present in GPS III satellites. Although the United States stopped the intentional degradation of GPS satellite signals in May 2000, this new action will result in the removal of SA capabilities, thereby eliminating a source of uncertainty in GPS performance that has been of concern to civil GPS users worldwide.
GPS benefits users around the world in many different ways, including aviation, road, marine and rail navigation, telecommunications, emergency response, resource exploration, mining and construction, financial transactions, and many more. All users, and their governments, have a stake in the future of GPS. The United States promotes international cooperation in the operation of civil global navigation satellite systems and continues to work to build international support for the protection of these signals from intentional interference and disruption.
I don’t know but if it helps Bush triangulate his way back to to conservatism, it will have been worth it.
Until an enemy uses the GPS signal in an attack.
Waiting for the NAU lunatics...
In the meantime, this sounds like the “Nuke” of GPS systmems, probably reserved for a worse case scenario where NO ONE except the US military can have a clue where they are going and how. (Zombie pandemic?)
Which begs the frigging question how the hell something this important is not classified. Heh, maybe one day we’ll reach a point where we are so advanced that we don’t have to classify anything.
“Yeah this is our Sooper-Dooper Seekret Stealth Fighter-Interceptor-Bomber-CSAR jet plane with plutonium armor piercing quad cannons and evil-seeking missiles that can exceed Mach 15. Can carry up to a company and comes equipped with a bar and swimming pool. Whacha gonna do about it, punks?”
Smart? It’s mostly irrelevant. Selective Availablity was based on intentionally introduced errors — vendors introduced differential GPS, which contacts 3 satellites and rejects the one that differs from the other 2. The new policy is just dumping a restriction that was wholly ineffective and irrelevant.
As long as we can turn off or “jangle” the system when the ICBMs are inbound, yes. Otherwise it’s suicide.
So the satellites grow on trees and fly themselves into space... how remarkable!
Sure it’s free. The government pays for it ;-)
Sounds like its a fart in the face to the Galileo system the Europeans have been trying to build.
That doesn't contradict what i wrote. A typical consumer unit contacts two satellites. Locating the source of a radio signal -- a process called triangulation for a reason -- takes three receivers. But if you start with the assumption that the target is on or slightly above the surface of the Earth, you can do it with two.
SA was a set of errors intentionally and randomly introduced by each satellite. That reduced the accuracy of the receiver. Vendors found a way to filter that out -- differential GPS units contacted three or more satellites at a time, when they could. They could then filter out the intentionally-introduced errors by ignoring, second by second, the satellite that disagreed with the others.
And plus or minus 100m isn't useless for weapons -- that claim would have been ludicrous even a decade or two ago. Few of the bombers or long-range rockets used in WWII, Korea or Vietnam had accuracy approaching the 100m range. Vietnam saw the first precision weapons, and the needed boots on the ground to "paint" the target with a laser. Even in the 1991 war with Iraq, most of the B-52s were tasked with carpet bombing using Vietnam-era surplus munitions, not precision weapons.
If a bomb doesn't kill or cripple its target, there are two equally accurate explanations -- it wasn't close enough or it wasn't big enough. A little bomb will get the job done at 10m. If you can only get within 100m, you just want to make a bigger crater.
To put things in perspective, suppose my target is one end zone of a football field. At the outer edge of a 100m accuracy radius, I'd land it in the opposite end zone of the same field. It would still suck to be in the stands, especially if I loaded my rocket with nerve gas.
I'm reasonably sure they kept the "off" switch. One thing is for sure, if they ever do turn it off there's going to be a whole lot of seriously lost pilots.....
10 meters is close enough for terrorists, I think, so it really doesn't matter.
Think of all the innovations these satellites have created in a capitalist society.
Not all government spending is wasted. The military builds something it needs, then thinks "gee, other folks might think this is pretty neat." And so we get cell phones, GPS, and oh yeah, the Intarwebs. Not to mention echolocation to spot schools of fish, Velcro (invented elsewhere but popularized by NASA), Tang, and even computers in general. They were invented to crack the Enigma code. Rockets, satellites, long-range telegraph wires, even carrier pigeons -- every advance in communications was driven by the military and then made available to everyone.
The military needed GPS. It was money well-spent. Making it available to everyone didn't cost any more. In fact, it opened up huge profit potential for the folks who make receivers and map sets, and poured billions back into the economy. It made it easier to use the Interstate highways -- another invention justified by military necessity that has reshaped civilian life.
The USPS just went GPS. Might be a link there.
I had wondered years ago why the postal service and UPS didn’t use GPS coordinates instead of street addresses.
For a true accurate reading three sats are required at a min the more the better. 100m as far as weapons goes are for weapons that use GPS and not say a land mine. Thus if off more than 10m a target for which a GPS aided weapon would be selected would result in a miss; most smart weapons look for about 3m. Yes vendors have found someways to get around the SA but government has found ways to put it back. And due to it being turned off for sometime most vendors have actually moved on from tryng to over come the government SA actions do to cost and need.
You must also take in to account that any damage done over and above the target will get the military hammered.
Our military, yes -- but they were never subject to SA, so thats moot. Our enemies don't give a good damn about collateral damage.
Good points. I fully agree. I was just poking fun at people who talk about things such as "free lunches" and "free health care." Those are things people should be able to take care of in most cases.
I don't have a problem with "free GPS" since I look at it as a group effort for the common good to make something we as individuals would rarely be able to do on our own. Same thing with some local, state, and federal projects.
I have used GPS on my laptop to keep me unlost many times and totally support spending for it.
Tang was a commercial product that kids wouldn’t drink - until they got NASA to fly it into space. Then every kid wanted to drink what the astronauts drank. At least you got it right that the hook and loop (velcro) was developed elsewhere (actually in WW II France.)
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