If the forum isn't particularly time sensitive, how about just not serving recent forum posts ( 1 week) to the search engine spiders, which advertise themselves as being such, no?
It has no effect at all in improving random errors caused by noise in the system, like ionospheric scintillation.
I honestly don't know how they compensate for all of the sources of error, but these systems are quite fancy. As far as scintillation goes, the severity of the effects seem localized to the segments of the ionosphere between you and each satellite. Given that you typically have more satellites available than you need for a proper fix, there is some room to monitor the health of each signal.
Multipath is a tough nut too, but the technology is there to limit the antenna's susceptibility to it, and to recognize when it is happening.
None of this is perfect, but it is pretty good, and with external aids like inertial systems, its not the neighborhood positioning system you seem to believe that it is.
Interesting. Do you need to be stationary for a period of time to calibrate your initial position?
Nope
As I was explaining in the previous post, accumulated doppler documents the relative motion of the satellites and you. Given esimates of the satellite position, and the observations at the base station, keeping track of your position is not that difficult if you keep count of the carrier cycles. The difficult part is figuring out that initial base line between you and the base station, and people smarter than me have managed to do a decent job of it, even recovering rather quickly after a loss of count like an overpass. Combine that with an inertial system, and the performance is amazing considering that the system doesn't use anything in its immediate environment to back track its motion (ie, triangulating off of local land marks). Not practical for everybody yet, but the time will come.
Think about how quickly the satellites are moving even when you are sitting still. Even then, you are only sitting still with respect to the surface of the planet, not with respect to the orbit of the satellites.
One neat side effect of measuring the doppler effect on the GPS signals, which is simply counting the carrier cycles and comparing it against the expected frequency, is that you are essentially keeping track of the relative range between you and the satellite. So once you figure out the ambiguity that locks in your position relative to the base station at one point in time, you don't need to figure them out again until you lose count of the cycles. Any changes since that time are reflected in the accumulated doppler. It's brilliant:)
You cannot use GPS to give you better measurements than the accuracy of the GPS constellation orbit determination
Yes, you can. I just woke up, but I'll see if I can explain.
In the case of DGPS, the reference station uses its surveyed coordinate to difference the time encoded in the signals it is receiving against the time it would expect given an estimation of where the satellite is. So any error in the satellite's predicted position is lumped in with all the other naturally occuring forms of error.
In the case of RTK, or other forms of relative carrier phase positioning, the system attempts to determine and track the difference in the number of cycles of the carrier wave of the GPS signal between the base and the satellite and the rover and the satellite. This number multiplied by the length of the carrier wave, 19cm for L1 signals, gives you the length of one side of a triangle between the base station, the rover, and the point between the rover and satellite that is as far from the satellite as the base station is. So, the exact position of the satellite is not as important as the sight line vector the satellite forms against the base line between the base station and rover. And given the great distance of the satellite from the typical base station and rover, jitter in the satellite's position doesn't change that vector much.
In conclusion, given the advances in relative positioning, limiting factors on GPS positioning today are the accuracy of the survey points, the ability of the electronics to precisely measure the carrier phase/doppler of the GPS signal, the quality of the clock in the GPS unit and the speed/accuracy of the algorithms that determine the carrier cycle count difference.
The relationship between GPS and UTC is broadcast from the constellation in the navigation data stream that also transmits time stamps, satellite ephemerises, a variety of correction parameters and other stuff I don't understand/remember:)
'apt-get source pkg' whatever you want configured differently, edit the debian/rules file, and fakeroot./debian/rules binary.
It's true that somebody hasn't taken the time to figure out the options for each program that match up to a flag like gnome, but I've only needed to locally recompile for odd things, like adding NAD27/83 datum shifting support for proj4.
There is also deb-make, which trivially converts any autoconf based source release into a practically proper debian package. I use that a bit more heavily.
Call me naive but, if that's what you want, why not buy a dell?
I have one. Its 2.5 years old with a 1600x1200 LCD. Its shoddy build quality has put it out of service though. I need to summon the energy to get it through tech support's head that the note to "update my video drivers" from the last time I sent it in has nothing to do with the laptop not turning on.
The one thing I hate about my Powerbook is its 1280x854 LCD resolution. I want to squeeze as many lines as possible in my terminals, and these shallow "widescreen" displays suck at it.
With this eMachine, I lose another 54 pixels, ugh. I want my 1280x1024 or 1600x1200 like Dell's UXGAs.
The number seemed a bit low at first. I stopped emptying my spam box in mid-October, and since then I've accumulated:
tugrul@firestarter:/tmp$ ls ~/Maildir/.SPAM/cur/ | wc
7156 7156 246731
So more than half the spam in the last 2.5 months of the year. Plus Spam Assassin is missing more spam since the onslaught of random word body spams... I'm thinking of spam binning all email with img tags, but I'd have to start white listing online vendors that have "pretty" receipts. *sigh*
So you're claiming that Microsoft has a record of not writing good software based upon a bug you found in a 1.0 version of a product?
No. The version of the product is really irrelevant to his main point, which you don't address in the process of deflecting.
The straw to break the camel's back was finding a significant bug in MDAC (which was acknowledged by a high-level tech once the ticket was escalated), and then having to wait 6 months for a fix.
I would expect more from a product I paid for, regardless of the vendor. Even the bias you may think the grandparent is operating under doesn't excuse the point.
If the graphics processor hangs (in the middle of a game for example), VPU Recover acts by resetting the VPU, enabling the end user to continue right where he left off. Depending on the state of the system when VPU Recover was activated, you may be able to recover with all of your open applications intact. In other cases, these applications may have to be closed and you're kicked back to the Windows desktop, but at least you don't have to go through the slow process of a complete system reboot. According to ATI, this feature is a requirement in Microsoft's next-generation Windows operating system, codenamed "Longhorn". So essentially, ATI is ahead of the curve, to the advantage of anyone who owns an ATI-based video card.
I couldn't find a neutral (not associated with the new ATI drivers) reference to this requirement. Wonder if this feature with manifest itself in ATI's promised regular updates to their Linux driver.
Anyone notice that while the sitefinder service was up, typos were beginning to get into the browser history since they didn't error out? And the next time you wanted to goto the same site, autocomplete would pick up the typo instead.
*mumble*
I'm just glad that was the worst that happened to me before this "service" got blocked here. I feel for the grandparent.
At first I didn't read the article, figuring that it was just a longer sappier version of the summary posted here. The summary does it no fucking justice.
More likely, ICANN caved under the pressure from some in the Internet community for whom this is a technology-religion issue about whether the Internet should be used for these purposes.
For this vocal minority, resentment lingers at the very fact that the Internet is used for commercial purpose, which ignores the fact that it's a critical part of our economy.
At this moment the veins in my forehead are bulging, and I'm envisioning a fate for this man pulled out of Crichton's Congo.
Apparently this gigantic ass doesn't realize that we are the critical people that make it function as a critical part of our economy. It also happens to be the fucking critical part of putting food on our plates. Somebody needs to get this through his thick head before the next time he hops into his 6 figure car heading back to his 7 figure house.
This unforgivable libel needs to be answered on the pages of news.com, and I think we should be petitioning to get this guy canned. He is not of the moral character I want near the big red button of the Internet.
It would be interesting if instead of typing in a mispelled name......it redirected you to a google search. I wonder how it would be received if they did that....and also didn't collect money from it, just offered it as a service....now THAT would be a better version of this whole fiasco, thats for sure.
Why bother theorizing the impossible? It is evident from their low key approach to introducing this service that they knew they were in the wrong. Why would they knowingly enter into such a situation unless motivated by profit?
I hate M$FT as much as the next guy here, but their autosearch solution was innovative* (* not sure if it was their idea). Without changing how the internet fundamentally works, they chose to render a failed DNS lookup as something more friendly and functional than a limited, rather useless OK popup. Something well within the right of a client application, and easily checked off if it doesn't float your boat. And it only affected those people that voluntarily chose to use their product (don't beat me up on the voluntarily bit).
With Verisign, there is no choice. They took a common community resource that should benefit all equally and biased it in their favor. They were selected as guardians of the system, not burdened with a mandate to "improve it". If they really think themselves clever, have them deploy a new, distinct system and compete for our patronage.
Here's a clue: want an anti-spam solution to work? Then start from the idea that it needs to make the life of the end user easier, not harder.
How could their life be easier? There is no accountability, and hence no burden in the current system. Anything we could possibly do would add complexity. Even the system your firm offers is a level of complexity... its not seen by the end user because they (a) pay you (b) permit somebody else to rifle through all their mail.
I was attracted to SPF less so for its spam prevention abilities than for its ability to communicate what servers I trust to send mail in my domain's name. And I think this will be the driving force behind its adoption. ISPs are already very interested in a system like this, as anyone that receives the blowback of forged spam would be. Its a matter of protecting one's identity.
You bring up an interesting possibility. If Verisign does manage to bring this back and pass it off as acceptable practice, what is to prevent ISPs from putting in wildcards to their own branded advertising search pages? Most people aren't savvy enough to change the DNS servers, let alone know what DNS is.
This is just a horrible path to go down, although it would be funny to see everyone else take the profits from Verisign's quick buck stunt.
Slashdot Mirror
Aye.
Man, I had forgotten how karma works here, no points to up vote you with :p
mythtv needs to do a popularity contest like debian does with packages.
Open source ratings, heh.
If the forum isn't particularly time sensitive, how about just not serving recent forum posts ( 1 week) to the search engine spiders, which advertise themselves as being such, no?
That gives you some elbow room.
It has no effect at all in improving random errors caused by noise in the system, like ionospheric scintillation.
I honestly don't know how they compensate for all of the sources of error, but these systems are quite fancy. As far as scintillation goes, the severity of the effects seem localized to the segments of the ionosphere between you and each satellite. Given that you typically have more satellites available than you need for a proper fix, there is some room to monitor the health of each signal.
Multipath is a tough nut too, but the technology is there to limit the antenna's susceptibility to it, and to recognize when it is happening.
None of this is perfect, but it is pretty good, and with external aids like inertial systems, its not the neighborhood positioning system you seem to believe that it is.
Interesting. Do you need to be stationary for a period of time to calibrate your initial position?
Nope
As I was explaining in the previous post, accumulated doppler documents the relative motion of the satellites and you. Given esimates of the satellite position, and the observations at the base station, keeping track of your position is not that difficult if you keep count of the carrier cycles. The difficult part is figuring out that initial base line between you and the base station, and people smarter than me have managed to do a decent job of it, even recovering rather quickly after a loss of count like an overpass. Combine that with an inertial system, and the performance is amazing considering that the system doesn't use anything in its immediate environment to back track its motion (ie, triangulating off of local land marks). Not practical for everybody yet, but the time will come.
On a moving vehicle?
Yes.
Think about how quickly the satellites are moving even when you are sitting still. Even then, you are only sitting still with respect to the surface of the planet, not with respect to the orbit of the satellites.
One neat side effect of measuring the doppler effect on the GPS signals, which is simply counting the carrier cycles and comparing it against the expected frequency, is that you are essentially keeping track of the relative range between you and the satellite. So once you figure out the ambiguity that locks in your position relative to the base station at one point in time, you don't need to figure them out again until you lose count of the cycles. Any changes since that time are reflected in the accumulated doppler. It's brilliant :)
Yes, you can. I just woke up, but I'll see if I can explain.
In the case of DGPS, the reference station uses its surveyed coordinate to difference the time encoded in the signals it is receiving against the time it would expect given an estimation of where the satellite is. So any error in the satellite's predicted position is lumped in with all the other naturally occuring forms of error.
In the case of RTK, or other forms of relative carrier phase positioning, the system attempts to determine and track the difference in the number of cycles of the carrier wave of the GPS signal between the base and the satellite and the rover and the satellite. This number multiplied by the length of the carrier wave, 19cm for L1 signals, gives you the length of one side of a triangle between the base station, the rover, and the point between the rover and satellite that is as far from the satellite as the base station is. So, the exact position of the satellite is not as important as the sight line vector the satellite forms against the base line between the base station and rover. And given the great distance of the satellite from the typical base station and rover, jitter in the satellite's position doesn't change that vector much.
In conclusion, given the advances in relative positioning, limiting factors on GPS positioning today are the accuracy of the survey points, the ability of the electronics to precisely measure the carrier phase/doppler of the GPS signal, the quality of the clock in the GPS unit and the speed/accuracy of the algorithms that determine the carrier cycle count difference.
The relationship between GPS and UTC is broadcast from the constellation in the navigation data stream that also transmits time stamps, satellite ephemerises, a variety of correction parameters and other stuff I don't understand/remember :)
'apt-get source pkg' whatever you want configured differently, edit the debian/rules file, and fakeroot ./debian/rules binary.
It's true that somebody hasn't taken the time to figure out the options for each program that match up to a flag like gnome, but I've only needed to locally recompile for odd things, like adding NAD27/83 datum shifting support for proj4.
There is also deb-make, which trivially converts any autoconf based source release into a practically proper debian package. I use that a bit more heavily.
Monkey Lives
Call me naive but, if that's what you want, why not buy a dell?
I have one. Its 2.5 years old with a 1600x1200 LCD. Its shoddy build quality has put it out of service though. I need to summon the energy to get it through tech support's head that the note to "update my video drivers" from the last time I sent it in has nothing to do with the laptop not turning on.
No more Dell.
The one thing I hate about my Powerbook is its 1280x854 LCD resolution. I want to squeeze as many lines as possible in my terminals, and these shallow "widescreen" displays suck at it.
With this eMachine, I lose another 54 pixels, ugh. I want my 1280x1024 or 1600x1200 like Dell's UXGAs.
tugrul@firestarter:/tmp$ grep "^ Folder:
14082 42246 902860
The number seemed a bit low at first. I stopped emptying my spam box in mid-October, and since then I've accumulated:
tugrul@firestarter:/tmp$ ls ~/Maildir/.SPAM/cur/ | wc
7156 7156 246731
So more than half the spam in the last 2.5 months of the year. Plus Spam Assassin is missing more spam since the onslaught of random word body spams... I'm thinking of spam binning all email with img tags, but I'd have to start white listing online vendors that have "pretty" receipts. *sigh*
Didn't think of that, and Safari ignored the Content-Type like another evil browser. Blah!
Mirror
Though not quite as elaborate, this reminds me of an applet a former professor of mine wrote for some amusement one day:
http://mrl.nyu.edu/~perlin/poetry2/
So you're claiming that Microsoft has a record of not writing good software based upon a bug you found in a 1.0 version of a product?
No. The version of the product is really irrelevant to his main point, which you don't address in the process of deflecting.
The straw to break the camel's back was finding a significant bug in MDAC (which was acknowledged by a high-level tech once the ticket was escalated), and then having to wait 6 months for a fix.
I would expect more from a product I paid for, regardless of the vendor. Even the bias you may think the grandparent is operating under doesn't excuse the point.
#2 seems to be on M$FT's mind as well.
If the graphics processor hangs (in the middle of a game for example), VPU Recover acts by resetting the VPU, enabling the end user to continue right where he left off. Depending on the state of the system when VPU Recover was activated, you may be able to recover with all of your open applications intact. In other cases, these applications may have to be closed and you're kicked back to the Windows desktop, but at least you don't have to go through the slow process of a complete system reboot.
According to ATI, this feature is a requirement in Microsoft's next-generation Windows operating system, codenamed "Longhorn". So essentially, ATI is ahead of the curve, to the advantage of anyone who owns an ATI-based video card.
Source
I couldn't find a neutral (not associated with the new ATI drivers) reference to this requirement. Wonder if this feature with manifest itself in ATI's promised regular updates to their Linux driver.
Anyone notice that while the sitefinder service was up, typos were beginning to get into the browser history since they didn't error out? And the next time you wanted to goto the same site, autocomplete would pick up the typo instead.
*mumble*
I'm just glad that was the worst that happened to me before this "service" got blocked here. I feel for the grandparent.
http://www.root-servers.org/
At first I didn't read the article, figuring that it was just a longer sappier version of the summary posted here. The summary does it no fucking justice.
More likely, ICANN caved under the pressure from some in the Internet community for whom this is a technology-religion issue about whether the Internet should be used for these purposes.
For this vocal minority, resentment lingers at the very fact that the Internet is used for commercial purpose, which ignores the fact that it's a critical part of our economy.
At this moment the veins in my forehead are bulging, and I'm envisioning a fate for this man pulled out of Crichton's Congo.
Apparently this gigantic ass doesn't realize that we are the critical people that make it function as a critical part of our economy. It also happens to be the fucking critical part of putting food on our plates. Somebody needs to get this through his thick head before the next time he hops into his 6 figure car heading back to his 7 figure house.
This unforgivable libel needs to be answered on the pages of news.com, and I think we should be petitioning to get this guy canned. He is not of the moral character I want near the big red button of the Internet.
I need to go cool off...
It would be interesting if instead of typing in a mispelled name......it redirected you to a google search. I wonder how it would be received if they did that....and also didn't collect money from it, just offered it as a service....now THAT would be a better version of this whole fiasco, thats for sure.
Why bother theorizing the impossible? It is evident from their low key approach to introducing this service that they knew they were in the wrong. Why would they knowingly enter into such a situation unless motivated by profit?
Somebody posted the definition of innovation earlier, noting that it didn't really clarify the nature of the change. Well, with these guys, you can be certain profit is a prerequisite to innovation.
I hate M$FT as much as the next guy here, but their autosearch solution was innovative* (* not sure if it was their idea). Without changing how the internet fundamentally works, they chose to render a failed DNS lookup as something more friendly and functional than a limited, rather useless OK popup. Something well within the right of a client application, and easily checked off if it doesn't float your boat. And it only affected those people that voluntarily chose to use their product (don't beat me up on the voluntarily bit).
With Verisign, there is no choice. They took a common community resource that should benefit all equally and biased it in their favor. They were selected as guardians of the system, not burdened with a mandate to "improve it". If they really think themselves clever, have them deploy a new, distinct system and compete for our patronage.
Here's a clue: want an anti-spam solution to work? Then start from the idea that it needs to make the life of the end user easier, not harder.
How could their life be easier? There is no accountability, and hence no burden in the current system. Anything we could possibly do would add complexity. Even the system your firm offers is a level of complexity... its not seen by the end user because they (a) pay you (b) permit somebody else to rifle through all their mail.
I was attracted to SPF less so for its spam prevention abilities than for its ability to communicate what servers I trust to send mail in my domain's name. And I think this will be the driving force behind its adoption. ISPs are already very interested in a system like this, as anyone that receives the blowback of forged spam would be. Its a matter of protecting one's identity.
You bring up an interesting possibility. If Verisign does manage to bring this back and pass it off as acceptable practice, what is to prevent ISPs from putting in wildcards to their own branded advertising search pages? Most people aren't savvy enough to change the DNS servers, let alone know what DNS is.
This is just a horrible path to go down, although it would be funny to see everyone else take the profits from Verisign's quick buck stunt.