For non-military use the GPS systems introduce inaccuracies.
No, GPS does not deliberately introduce inaccuracy - that was part of selective availability, which was turned off in 1998. What GPS does do is not make available to civilians the correction mechanism that enable military grade accuracy.
The accuracy of civilian GPS units (within what's available from the system) is mostly dependent on factors outside of the government's control... The design of the antenna, how well it's matched to the receiver, the accuracy and stability of the clock circuits, etc... etc... all effect the accuracy of the GPSr.
Is there an algorithm that would bring the resolution down from 10 meters to 1 meter or less?
Using WAAS corrections, even a cheap-ass handheld unit can routinely obtain accuracies under 5m, and accuracies under 3m are not unheard of. Surveyor grade GPSr's can obtain sub-meter (down to centimeter) accuracy using GPS alone, but require that the receiver be stationary for extended periods (a couple of hours) and use high quality antennas and electronics. (Which is why they cost $10k+.)
Would be possible to get a more accurate position if a receiver combined the various GPS systems - as a kind of check/balance.
Yes, and such units are commercially available, but generally only in higher end units because you're essentially buying two systems in one box.
Something I didn't realize until recently is that in the northern latitudes (Canada, northern US), GPS coverage has occasional small gaps in it.
It doesn't. The constellation's orbital pattern is uniform across the entire surface of the Earth.
My John Deere dealer was saying that in some areas every few days about 6pm (happens to be that time in those areas) GPS coverage drops below 1 meter accuracy levels, and in those areas GPS guidance on farm machines becomes unusable for about an hour or so.
Your John Deere dealer is a little shaky on how GPS operates. The birds are in 12 hour sidereal orbits, which means the pattern (as seen from an fixed location on Earth) repeats every 11 hours and 56 minutes.... Which means (if such an effect as he describes existed) it would steadily and regularly drift earlier through the day. Thus not only would the effect be seen 'about 6PM' every two weeks or so, but it would also be visible at varying times through the day for a week roughly every other week. (This also implies the gaps drift across the Earth's surface in a regular pattern, and would be visible in places other than the northern latitudes.) In addition, he may not realize that GPS accuracy *normally* varies somewhat over spans of a few hours as the geometry of the visible portion of the constellation varies. So what he's seeing is something else, amplified by observer bias.
As well sometimes a satellite goes offline for maintenance.
Yes, they do. But the system is designed and operated such that having a bird offline for maintenance degrades total system performance by only a very small amount.
As agriculture is becoming very reliant on GPS (hence John Deere lobbying in washington against LTE usage of adjacent frequencies), this is a problem.
The problem isn't the GPS system. The problem is John Deere is trying to use the system at an accuracy (100% availability at 1m) greater than the specified [civilian] performance levels (95% availability at 7m).
I can verify that some machine tool parts I have recent received were stamped as made in India. No punchline, none of that. For real.
Quality, fit, finish, were all about the same as Chinese, in other words, technically meets the bare minimum, but not much more.
Quality, fit, and finish are a consequence of the specifications set, and the QA efforts expended, by the buyer who contracts with the manufacturer. NOT BY THE COUNTRY WHERE THE MANUFACTURING TAKES PLACE. If you buy from high quality vendors, you'll get high quality parts/tools, even if they were manufactured in Bumfuckistan. If you buy cheap crap, you'll get cheap crap even if it was manufactured in Michigan.
Despite both being manufactured in China, there's a reason why my $99 set of house brand DIYer grade woodworking tools have been replaced by about $500 worth of brand name contractor grade tools.
Earth is getting saturated. Soon only India will be left as cheap labor.
Nope, after India there is Africa, and considerable portions of Central and South America. But Africa is really the big one to watch for over the next couple of decades.
Will there ever be an expanding economy when there is no cheap labor left?
To some extent, yes. (After all, it happened in the US from the 40's to the 70's, and in Japan from the 70's to the 80's.) But it's a very fragile state.
The only thing going for organic is taste, however, that is probably due to most "organic" food being produced closer to the consumer than non-organic food.
70% of the "organic" food sold in the US is raised in California. 20% is raised in Mexico. 5% elsewhere in the world.
Except that it does mean something in practice. In the US, use of the word "organic" is regulated
Yes, it's "regulated". So loosely as to be almost meaningless - to the benefit of the rising megacorps and their stockholders that serve the grocery chains.
"Vanity Fair has a story questioning the true value of TSA security."
Well, no, it doesn't question the value of TSA security. It's regurgitates Schneier's propaganda line without question, analysis, or critical thinking. It's great publicity for Schneier, without which he (as a consultant and pundit) cannot survive. Otherwise, it's pretty much useless.
It's funny, if Vanity Fair parroted Dvorak, or Cringely, or any of Slashdot's other whipping boys - they'd be taken to task for crappy journalism and reprinting press releases. But, once again, the double standard rears it's ugly head - parrot someone (undeservedly) regarded as an 'expert' and beloved of Slashdot, and they get a free pass.
the only people still masturbating furiously over Tesla motors and electric cars in general are people who dont understand that the automobile as a means of personal conveyance is unsustainable no matter what you fuel you choose. If you dont believe me, try getting from long beach to downtown LA at 7:30 am.
For the 99.99% percent of US citizens who don't live in LA, and the 90% of us who don't live in huge megalopoli, that's pretty much a useless metric.
where Xerox marketed the Xerox Alto as the first commercial GUI driven computer in 1973? I'm guessing technology would have advanced to todays levels by the early 90s
Why? Today's (computer/IT) tech is largely driven by the ubiquitous PC and the availability of really cheap microprocessors. GUI's don't enable either. Nor will GUI's make mini- and micro- computers any cheaper, in fact they'll hog processing power (making them less attractive) and/or raise the price of their graphic terminals (ditto).
Everybody who is saying that nobody needs trade shows to make announcements in the internet age is right.
But what 'everyone' is missing is that there is more to trade shows (much more) than just announcements.
Quite frankly that trade shows for other industries are less effected so far is probably more an indicator of lag than anything else.
In other words, you've assumed yourself to be correct, and any evidence otherwise is just more evidence you're correct.
I think that for things like cars and planes trade shows will be eternal, simply because their physicality is so important. Gadgets are sold on feature lists. Even while features remain important to purchasing decisions, vehicles are sold on a visceral impression of their sturdiness, comfort, and design. Because safety and ease of maintenance etc. are so important to vehicles, people really want to be able to touch them to be assured of their quality before they sign any commitment that might put themselves at risk.
You honestly believe people go to the Paris Air Show only to see something they could see any day of the week by simply visiting the manufacturer? You really are deluded.
As I said, there's more to the world than IT. There's also much more to the world than 'gadgets'. Grow up and get out of your parent's basement.
Trade shows are largely a relic of the pre-Internet world.
That certainly neatly explains the continued growth of PAX doesn't it?
We've seen technology-driven companies moving away from announcing and/or releasing products at mega-trade shows especially over the past 4-5 years, whether they're computer companies (Apple, Microsoft), camera companies (Nikon, Canon), or "we do it all and do it badly" companies (Sony).
Not so much for camera makers - Photokina is still a very big deal. The Paris Air Show is still a big deal in the aviation world as well. Etc... etc...
There's more to world of trade shows than just IT geekfests.
Conversely, it's surprising how little the Japanese tsunami affected the tech world. I guess their industries were concentrated further south.
The camera world, OTOH, was hit pretty heavily by the tsunami. All of the big manufacturers lost significant chunks of their production capacity, and the effects are still being felt in terms of shortages, delays in introducing new models, etc...
High quality software isn't cheap either, not to mention the incomparable joy of re-buying it every couple of years as the underlying hardware and OS changes. (Not to mention that a quick google finds that preserved rats in small quantities cost around $9-20.00, so they aren't that expensive.) Also, in an educational setting (unless you just toss 'em the assignment and walk away), you still have a very high investment of time and effort from professors and assistants.
So I can't see any real gains in time or money in shifting to simulators. Not that there's a shortage of either.
But the best part is that once you fix a bug in an automated system, it's fixed forever
Only so long as the software, hardware, operating system, real world environment (physical, regulatory, etc..) you operate in, etc... etc... remain fixed and unchanging forever.
You state that as if it were a fact, when the reality is your trying to substitute "cheaper' for 'efficient" and hope nobody notices. And it's not a matter of "a little latency", it a matter of 'a huge list of things robots can't do". (Or once again, you're trying to move goalposts and change definitions, while hoping vainly nobody notices.)
Like you say there are things that humans can do better sometimes, but dragging the rover out of the ditch isn't a good example: If it was a robot, we'd just shrug and send off another one thereby increasing the cost of the mission from 1% of Apollo to 2%.
Right, which is why a replacement for Spirit is cruising across the Martian surface even now... Oh, wait - it's on it's way to Mars. Oh, that's right, it's under construction...
Well, no, once again you're not only wrong - but stupid. We aren't sending a replacement even though it got stuck.
That's not to say I'm against manned spaceflight generally.
I never said you were, only that your reasons and reasoning for not supporting it are deeply flawed. Like your laughable mathematics that you opened your reply with - which look reasonable, only so long as you are utterly ignorant of what was actually accomplished by either program.
Longer term, let the commercial sector work on manned spaceflight for a while. They'll get the costs down in ways NASA can't dream of.
The commercial sector could drop transport costs by a factor of a thousand - and barely budge the costs of manned exploration. Launches are relatively cheap, even now. Hardware and operations are not.
You don't haul cargo in the same vehicle as humans. Cargo doesn't need the super-expensive "last 1%" reliability that a human crew demands.
Right - which is why all the unmanned cargo rockets have pretty much the same reliability as the manned boosters. In reality, yes, cargo does require that reliability because they costs billions of dollars and nobody is going to put cargo that valuable on anything but the best.
You don't need humans up there at all. The future, for a generation or two at least, is unmanned exploration of the solar system. Look at where virtually all the meaningful scientific knowledge has come from in the last 20 - 40 - 60 years: unmanned probes.
This sounds suspiciously like you've defined yourself into a circle - by using the weasel word 'meaningful'. I'd consider the results of the analysis of the rocks brought back by Apollo (manned BTW) pretty meaningful. (Not to mention all the science that's *not* part of the space program.)
You also fail to consider just how slow and limited unmanned craft are: In just four days on the Moon, the Apollo 16 rover (manned) covered 7.2 miles. In five *years* on Mars, Spirit covered just 5 miles. (The couple of times the Lunar Rover became stuck, either the crew drove it out with a few minutes work, or in one instance they picked the Rover up and turned it so that it was on better ground.) Between the two of them, in twelve *years* worth of combined operations, the Mars rovers have covered 25 miles. In total driving time of eight *hours* (and total surface time of nine *days*) the Lunar rovers covered a combined 27 miles. And when you count in the time spent on foot across all the Apollo missions...
You also fail to consider that currently, everywhere it's practical to send men rather than robots - we send men. Whether it's inside a failed nuclear reactor, on the Antartic ice sheet, or at the bottom of the ocean. Robots just aren't as versatile as a people.
Where the 'science' consists of just collecting raw data, like the strength of a magnetic field or taking pictures by the gross lot, yeah, robots rule. But once you want to do anything but simple repetitive tasks, robots fall way behind.
if this were turned over to private industry they would centralize the entire project in one or two locations and piss off a lot of congress people who currently have a piece of the pie.
In some universe where this was trivially done and wouldn't require years of construction and tens of billions of dollars in investment - this would be a sensible statement. But, as with so many comments on the Shuttle, you're wildly disconnected with reality.
If the Shuttle cost a half a billion per launch, you'd have a point. But the truth is, in cash out of pocket, the shuttle costs less than a hundred million per launch. The balance is either the amortized share of fixed costs, or the amortized share of sunk costs like construction and R&D.
Just as with so much else with high overhead, the solution to the Shuttle's 'cost' problems shouldn't have been to stop flying it - it should have been to fly it more.
And it was very expensive compared to alternative methods of getting things into space. Falcon 9 Heavy should be able to put more payload into space for a tenth of the price.
In a universe where just throwing raw loads of mass into orbit as cheaply as possible is the goal of the space program... that would be useful. But that's not the goal, and never has been.
A subcompact is cheaper than an RV or a tow truck, but nobody would ever confuse the two or send the former to do either of the latter's job. Yet, when it comes to space, such delusion is common, nay - expected.
Slashdot Mirror
No, GPS does not deliberately introduce inaccuracy - that was part of selective availability, which was turned off in 1998. What GPS does do is not make available to civilians the correction mechanism that enable military grade accuracy.
The accuracy of civilian GPS units (within what's available from the system) is mostly dependent on factors outside of the government's control... The design of the antenna, how well it's matched to the receiver, the accuracy and stability of the clock circuits, etc... etc... all effect the accuracy of the GPSr.
Using WAAS corrections, even a cheap-ass handheld unit can routinely obtain accuracies under 5m, and accuracies under 3m are not unheard of. Surveyor grade GPSr's can obtain sub-meter (down to centimeter) accuracy using GPS alone, but require that the receiver be stationary for extended periods (a couple of hours) and use high quality antennas and electronics. (Which is why they cost $10k+.)
Yes, and such units are commercially available, but generally only in higher end units because you're essentially buying two systems in one box.
It doesn't. The constellation's orbital pattern is uniform across the entire surface of the Earth.
Your John Deere dealer is a little shaky on how GPS operates. The birds are in 12 hour sidereal orbits, which means the pattern (as seen from an fixed location on Earth) repeats every 11 hours and 56 minutes.... Which means (if such an effect as he describes existed) it would steadily and regularly drift earlier through the day. Thus not only would the effect be seen 'about 6PM' every two weeks or so, but it would also be visible at varying times through the day for a week roughly every other week. (This also implies the gaps drift across the Earth's surface in a regular pattern, and would be visible in places other than the northern latitudes.) In addition, he may not realize that GPS accuracy *normally* varies somewhat over spans of a few hours as the geometry of the visible portion of the constellation varies. So what he's seeing is something else, amplified by observer bias.
Yes, they do. But the system is designed and operated such that having a bird offline for maintenance degrades total system performance by only a very small amount.
The problem isn't the GPS system. The problem is John Deere is trying to use the system at an accuracy (100% availability at 1m) greater than the specified [civilian] performance levels (95% availability at 7m).
Quality, fit, and finish are a consequence of the specifications set, and the QA efforts expended, by the buyer who contracts with the manufacturer. NOT BY THE COUNTRY WHERE THE MANUFACTURING TAKES PLACE. If you buy from high quality vendors, you'll get high quality parts/tools, even if they were manufactured in Bumfuckistan. If you buy cheap crap, you'll get cheap crap even if it was manufactured in Michigan.
Despite both being manufactured in China, there's a reason why my $99 set of house brand DIYer grade woodworking tools have been replaced by about $500 worth of brand name contractor grade tools.
Nope, after India there is Africa, and considerable portions of Central and South America. But Africa is really the big one to watch for over the next couple of decades.
To some extent, yes. (After all, it happened in the US from the 40's to the 70's, and in Japan from the 70's to the 80's.) But it's a very fragile state.
It's not even the detector part(s) (there are seven such) - it's *a* detector.
70% of the "organic" food sold in the US is raised in California. 20% is raised in Mexico. 5% elsewhere in the world.
You do the math.
Yes, it's "regulated". So loosely as to be almost meaningless - to the benefit of the rising megacorps and their stockholders that serve the grocery chains.
"Vanity Fair has a story questioning the true value of TSA security."
Well, no, it doesn't question the value of TSA security. It's regurgitates Schneier's propaganda line without question, analysis, or critical thinking. It's great publicity for Schneier, without which he (as a consultant and pundit) cannot survive. Otherwise, it's pretty much useless.
It's funny, if Vanity Fair parroted Dvorak, or Cringely, or any of Slashdot's other whipping boys - they'd be taken to task for crappy journalism and reprinting press releases. But, once again, the double standard rears it's ugly head - parrot someone (undeservedly) regarded as an 'expert' and beloved of Slashdot, and they get a free pass.
For the 99.99% percent of US citizens who don't live in LA, and the 90% of us who don't live in huge megalopoli, that's pretty much a useless metric.
Why? Today's (computer/IT) tech is largely driven by the ubiquitous PC and the availability of really cheap microprocessors. GUI's don't enable either. Nor will GUI's make mini- and micro- computers any cheaper, in fact they'll hog processing power (making them less attractive) and/or raise the price of their graphic terminals (ditto).
I'm glad I'm a Canon shooter. [/brandflamewars] :)
But more seriously, it's just annoying sometimes how provincial Slashdot can often be.
Take it up with the source of your schools funding - your local taxing district.
But what 'everyone' is missing is that there is more to trade shows (much more) than just announcements.
In other words, you've assumed yourself to be correct, and any evidence otherwise is just more evidence you're correct.
You honestly believe people go to the Paris Air Show only to see something they could see any day of the week by simply visiting the manufacturer? You really are deluded.
As I said, there's more to the world than IT. There's also much more to the world than 'gadgets'. Grow up and get out of your parent's basement.
That certainly neatly explains the continued growth of PAX doesn't it?
Not so much for camera makers - Photokina is still a very big deal. The Paris Air Show is still a big deal in the aviation world as well. Etc... etc...
There's more to world of trade shows than just IT geekfests.
The camera world, OTOH, was hit pretty heavily by the tsunami. All of the big manufacturers lost significant chunks of their production capacity, and the effects are still being felt in terms of shortages, delays in introducing new models, etc...
High quality software isn't cheap either, not to mention the incomparable joy of re-buying it every couple of years as the underlying hardware and OS changes. (Not to mention that a quick google finds that preserved rats in small quantities cost around $9-20.00, so they aren't that expensive.) Also, in an educational setting (unless you just toss 'em the assignment and walk away), you still have a very high investment of time and effort from professors and assistants.
So I can't see any real gains in time or money in shifting to simulators. Not that there's a shortage of either.
If there was a shortage of those resources, you'd have a point. Since there isn't, you're just handwaving buzzwords around.
Only so long as the software, hardware, operating system, real world environment (physical, regulatory, etc..) you operate in, etc... etc... remain fixed and unchanging forever.
Is being that clueless and ignorant a natural talent, or did you have to study?
In a world where launch costs dominate program costs, that would be a reasonable claim. But we don't live in such a world. Not even close.
You state that as if it were a fact, when the reality is your trying to substitute "cheaper' for 'efficient" and hope nobody notices. And it's not a matter of "a little latency", it a matter of 'a huge list of things robots can't do". (Or once again, you're trying to move goalposts and change definitions, while hoping vainly nobody notices.)
Right, which is why a replacement for Spirit is cruising across the Martian surface even now... Oh, wait - it's on it's way to Mars. Oh, that's right, it's under construction...
Well, no, once again you're not only wrong - but stupid. We aren't sending a replacement even though it got stuck.
I never said you were, only that your reasons and reasoning for not supporting it are deeply flawed. Like your laughable mathematics that you opened your reply with - which look reasonable, only so long as you are utterly ignorant of what was actually accomplished by either program.
The commercial sector could drop transport costs by a factor of a thousand - and barely budge the costs of manned exploration. Launches are relatively cheap, even now. Hardware and operations are not.
Right - which is why all the unmanned cargo rockets have pretty much the same reliability as the manned boosters. In reality, yes, cargo does require that reliability because they costs billions of dollars and nobody is going to put cargo that valuable on anything but the best.
This sounds suspiciously like you've defined yourself into a circle - by using the weasel word 'meaningful'. I'd consider the results of the analysis of the rocks brought back by Apollo (manned BTW) pretty meaningful. (Not to mention all the science that's *not* part of the space program.)
You also fail to consider just how slow and limited unmanned craft are: In just four days on the Moon, the Apollo 16 rover (manned) covered 7.2 miles. In five *years* on Mars, Spirit covered just 5 miles. (The couple of times the Lunar Rover became stuck, either the crew drove it out with a few minutes work, or in one instance they picked the Rover up and turned it so that it was on better ground.) Between the two of them, in twelve *years* worth of combined operations, the Mars rovers have covered 25 miles. In total driving time of eight *hours* (and total surface time of nine *days*) the Lunar rovers covered a combined 27 miles. And when you count in the time spent on foot across all the Apollo missions...
You also fail to consider that currently, everywhere it's practical to send men rather than robots - we send men. Whether it's inside a failed nuclear reactor, on the Antartic ice sheet, or at the bottom of the ocean. Robots just aren't as versatile as a people.
Where the 'science' consists of just collecting raw data, like the strength of a magnetic field or taking pictures by the gross lot, yeah, robots rule. But once you want to do anything but simple repetitive tasks, robots fall way behind.
In some universe where this was trivially done and wouldn't require years of construction and tens of billions of dollars in investment - this would be a sensible statement. But, as with so many comments on the Shuttle, you're wildly disconnected with reality.
If the Shuttle cost a half a billion per launch, you'd have a point. But the truth is, in cash out of pocket, the shuttle costs less than a hundred million per launch. The balance is either the amortized share of fixed costs, or the amortized share of sunk costs like construction and R&D.
Just as with so much else with high overhead, the solution to the Shuttle's 'cost' problems shouldn't have been to stop flying it - it should have been to fly it more.
In a universe where just throwing raw loads of mass into orbit as cheaply as possible is the goal of the space program... that would be useful. But that's not the goal, and never has been.
A subcompact is cheaper than an RV or a tow truck, but nobody would ever confuse the two or send the former to do either of the latter's job. Yet, when it comes to space, such delusion is common, nay - expected.