21–30 of 43 posts
is centimeter accuracy even possible with GPS? http://www.gps.gov/systems/augmentations/ cites 10-15 centimeter accuracy under their NDGPS modernization efforts, but don't even say they've gotten there yet.
It's not possible, even with pretty ideal conditions. Edit: I excluded RTK stuff in that comment :)
Earlier quoted context omitted.
It is, using RTK (real time kinematic) and 2 different receivers: http://www.kickstarter.com/projects/swiftnav/piksi-the-rtk-g...
Yes but that somewhat limits the practicality because you need two receivers, a clear signal path between them and one has to be relatively static. It's fine for surveying but for dynamic applications which are far more common, it's a pain.
The US Navy has been doing accurate position determination using ZERO satellite availability. How do you think a submarine knows where it is?
You can already get a $20 GPS module, Arduino compatible. Just take any random GPS mouse, they will be talking NMEA over some serial line. Of course you don't get "centimeter accurate", but that's a lie anyway, so nothing lost.
GPS mouse? Unless you mean module (DYAC), can you please give a pointer?
http://www.royaltek.com/index.php/rgm-3600
There are dozens of variants, some with USB, some with RS232, some with bluetooth. "Mouse" is common nomenclature for this kind of device, I don't know why.
Basically, they all deliver continuous NMEA data over a serial line.
Take a look at the amount of work that the Teensy3 community has done to make Arduino (atmel) specific libraries compatible with the ARM chip on the Teensy3. They're one of the few communities that have wide-ranging support with an ARM chip, but have put in a lot of time and effort to get it there.
You can already get a $20 GPS module, Arduino compatible. Just take any random GPS mouse, they will be talking NMEA over some serial line. Of course you don't get "centimeter accurate", but that's a lie anyway, so nothing lost.
I funded hoping for a couple. I imagine the centimetre accuracy will be hard yo achieve,but what sort of accuracy is required to calculate average speed over 200 m to within 2 km/h? Suppose you smooth the input will it be sufficient or does 2 m accuracy mean that it oscillates so wildly within that circle that it's only worth it for positioning alone?
200/t +/- x/t m/s
For a snail, you don't even need a GPS; just say "2 km/h" and you will be within 2 km/h.
However, things are better, as measuring errors for GPS for nearby (in time and place) positions aren't independent. If your position is of by x meters in direction D now, chances are it will still be more or less of by x meters in direction D in a few seconds.
Back to your question: I wouldn't know, but I think you want to rephrase it in terms of relative error or specify at what speed you want to know the answer.
[1] the math is the other way around, but that doesn't matter much.
is centimeter accuracy even possible with GPS? http://www.gps.gov/systems/augmentations/ cites 10-15 centimeter accuracy under their NDGPS modernization efforts, but don't even say they've gotten there yet.
It's not possible, even with pretty ideal conditions. Edit: I excluded RTK stuff in that comment :)
Earlier quoted context omitted.
It is, using RTK (real time kinematic) and 2 different receivers: http://www.kickstarter.com/projects/swiftnav/piksi-the-rtk-g...
Yes but that somewhat limits the practicality because you need two receivers, a clear signal path between them and one has to be relatively static. It's fine for surveying but for dynamic applications which are far more common, it's a pain.
http://igs.bkg.bund.de/ntrip/index
http://en.wikipedia.org/wiki/Networked_Transport_of_RTCM_via... nternet_Protocol
Earlier quoted context omitted.
It is, using RTK (real time kinematic) and 2 different receivers: http://www.kickstarter.com/projects/swiftnav/piksi-the-rtk-g...
Yes but that somewhat limits the practicality because you need two receivers, a clear signal path between them and one has to be relatively static. It's fine for surveying but for dynamic applications which are far more common, it's a pain.
You can already get a $20 GPS module, Arduino compatible. Just take any random GPS mouse, they will be talking NMEA over some serial line. Of course you don't get "centimeter accurate", but that's a lie anyway, so nothing lost.
GPS mouse? Unless you mean module (DYAC), can you please give a pointer?
The term "GPS mouse" refers to the shape and size of the device, and has come to mean any wired or wireless GPS receiver that doesn’t come with any sort of interface. It merely outputs position data to a laptop, cell phone, etc.