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Russian GPS Alternative Near Completion
Russia has successfully launched another round of GLONASS satellites bringing the grand total to 18 of the navigational units online. "The GPS competitor -- first begun in the Soviet era and only recently revived after years of post-collapse neglect -- is now theoretically capable of providing coverage to the entire Russian territory, with First Deputy Prime Minister Sergei Ivanov claiming that the first compatible consumer devices will be available in the middle of next year. By 2010 Russia plans to open the system up to outside nations as well, contributing to an eventual three- or even four-system global market"
Selective Availability hasn't been used since the Clinton administration. Sure, they can degrade the signal in certain areas, but it's rarely done.
If by 'only the most modern', you mean 'the majority of the GPS receivers made in the last 10 years', then yes. WAAS wasn't around back in the days of GPS infancy, but most new receivers have it, and yes
... and most times it doesn't work anyway Now that's just wrong. The FAA (Federal Aviation Administration) designed WAAS to allow aircraft to shoot approaches into airports. I help design aircraft GPS systems for a living, so I can tell you a thing or two about GPS/WAAS integrity. I'd trust my life to it, as do the pilots that use it daily. There are many systems in place to ensure that the position given is accurate (ionospheric correction, signal degradation parameters, step detection, etc), and other systems that ensure that all the satellite signals are doing what they're supposed to (RAIM, FDE, etc). Please read up on WAAS when you get a chance, you'd be surprised how well it works.http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System
Because these systems are primarily used by military. With the total dependability that modern military systems place on them no nation in their right mind would want an outside force controlling them.
WAAS does not work particularly well on the ground. Most people seem to care about this, more so than whether it works well for it's intended use. Aircraft navigation on approach.
The biggest issue with WAAS being that those of us in the central area of North America may have both satellites very near the horizon. If you are on either coast one satellite is high enough above the horizon to be clear line of sight past most ground obstacles. exceptions being large nearby buildings, or mountains.
Of course, I don't see much difference in usage on the ground with, or without waas. Ground based clutter causes other error types anyway and you have to use GPS as an aid, not as a solution to a non-existent problem. It works and it works damn well, but it won't auto-navigate your car through traffic.
My own experiments with GPS would bear this out.
When I was doing more of this stuff, clients would sometimes take several GPS points, and find to their delite that nearly always the three points were much closer than the supposed precision of plain old non-differential GPS. As a result, they began to assume the system had more precision than rated.
Intrigued by this I set up a fixed station that tracked all the fixes coming out of the receiver over several hour period. What I found is that sequential readings tended to be strongly correlated to their immediate predecessors but weakly correlated to fixes taken much earlier. Essentially the receiver would report all the points as being in a smallish bucket a couple of meters wide, but every fifteen or twenty minutes it would pick up the bucket and put it a different place five or even ten meters away. Then there'd be a run for fifteen minutes or so at the new "bucket position", after which the bucket would move once again.
The way I interpret this is that the various sources of error change as a satellite's position changes. Perhaps a mountain range gives a strong reflection in one position or not another, or perhaps a new satellite rises (or an old one sets), leading to a whole new set of data.
So, it stands to reason that having more than twice the number of satellites means that the various random sources of error would tend to be averaged out more, provided any difference between the old and new system could be accounted for systematically.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
For those of us in land surveying, having another few satelites is very important if your in a hurry. My current equipment (Topcon Hiper-lite) can obtain accuracy of less than 1 cm in less than 2 minutes just using the US GPS satelites and more accurate in less time using both US GPS and Russian GLONASS. Also, here are a few other interesting facts associated with GPS for Surveyors (who need sub-centimeter accuracy) 1) The more satelites the better (and my equipment which happens to be rebadged JAVAD) has been getting signals from GPS and GLONASS for a few years already, 2) The US stopped encoding the GPS signals under executive directive a year or more ago, and 3) The Eurpoean Union is working to put up their own GPS network which the latest generation of commercial survey grade receivers are already prepared for. So, for those of us whose business requires GPS, the article seems to be more about political posturing and less about anything new system-wise.
the most widespread consumer gps chipset is sirf star II. it doesn't support dgps.
only the latest generation of consumer gps chipsets (sirf star III and alike) does support it. and it doesn't work well on the ground so pilots and navy are pretty much only ones who can use it.
you might not believe it, but either ones are among a minority of gps users.
"It's such a fine line between stupid and clever" -- David St. Hubbins, Spinal Tap
This is actually the second time GLONASS has become fully operational. The first time was back on February of 1996 (see 'Understanding GPS Principles and Applications' for details). However, older satellites started failing soon after and they weren't able to replace them quickly enough so the constellation quickly degraded in functionality.
You make it sound 100% cynical, that the folks in favor of defense spending don't really believe it's needed. Every single soul who wants increased defense spending is a heartless bastard who doesn't care about the future, has filthy-rich buddies, doesn't care if there are millions of innocent dead, etc.
It's a good idea to take your government with a grain of salt, but this is just over-the-top.
I guess I should post a rant about the cynical leftists who keep people poor forever so that they can justify raising taxes to pay welfare benefits, who want minorities oppressed to make sure they never vote Republican, etc. But two strawmen do not make a right.
Whenever I hear or read something really extreme that I disagree with, I try to remind myself that it's likely that the extreme person is basically a decent person, and if I got to know them I might like them. If I got to know you, I might like you, even though you come off sounding like my political enemy. (And before you knee-jerk... I'm more of a small-l libertarian than anything else, but defense spending is IMHO one of the few legitimate things for government to be doing.)
It's a jerkoff forum spammer that keeps jumping into conversations with supposed links to interesting and relevant tidbits that all point through various redirects to his own useless site.
The higher the technology, the sharper that two-edged sword.
If you are getting 10 satellites with strong L2 signals you are lucky. At 40 degrees north I rarely have eight satellites with decent L2 SNRs, and really appreciate the extra 1 to 3 sats GLONASS gives me. I'm talking about a Trimble R8 model 2, arguably the best GPS antenna and receiver on the market today.