Re: [talk-au] new toy found by son

2009-10-01 Thread John Smith
2009/10/2 Sam Couter : > I thought AGPS didn't help with accuracy, it just helps with faster > satellite aquisition by downloading ephemeris data instead of searching > blindly for visible satellites. It won't help with surveying a tunnel. Depends what type of AGPS I think, in the case of phone ne

Re: [talk-au] new toy found by son

2009-10-01 Thread Sam Couter
John Smith wrote: > Or just use a phone with AGPS from the phone network, when I have 3G > connectivity on the phone I usually get 2m accuracy and works inside > buildings etc. Now we just need 3G connectivity Australia wide :D I thought AGPS didn't help with accuracy, it just helps with faster s

Re: [talk-au] new toy found by son

2009-10-01 Thread John Smith
2009/10/1 Elizabeth Dodd : > On Thu, 1 Oct 2009, John Smith wrote: >> > On Thu, 1 Oct 2009, John Smith wrote: >> >> Oh that's easy then, get him to figure out how to semi-sync with the >> >> secondary GPS frequency, which is what high end surveying equipment >> >> does, you don't need to lock onto

Re: [talk-au] new toy found by son

2009-10-01 Thread Elizabeth Dodd
On Thu, 1 Oct 2009, John Smith wrote: > > On Thu, 1 Oct 2009, John Smith wrote: > >> Oh that's easy then, get him to figure out how to semi-sync with the > >> secondary GPS frequency, which is what high end surveying equipment > >> does, you don't need to lock onto the signal, just get close enough

Re: [talk-au] new toy found by son

2009-10-01 Thread John Smith
2009/10/1 Elizabeth Dodd : > On Thu, 1 Oct 2009, John Smith wrote: >> Oh that's easy then, get him to figure out how to semi-sync with the >> secondary GPS frequency, which is what high end surveying equipment >> does, you don't need to lock onto the signal, just get close enough to >> calculate th

Re: [talk-au] new toy found by son

2009-10-01 Thread Elizabeth Dodd
On Thu, 1 Oct 2009, John Smith wrote: > Oh that's easy then, get him to figure out how to semi-sync with the > secondary GPS frequency, which is what high end surveying equipment > does, you don't need to lock onto the signal, just get close enough to > calculate the atmospheric effects on the L1 s

Re: [talk-au] new toy found by son

2009-10-01 Thread John Smith
2009/10/1 : > Accelerometers would be an excellent solution for mapping tunnels though. > Especially since you're only talking about a short-ish time span and you can > potentially have 2 accurate calibration points (one at each end of the > tunnel). I guess if the accelerometer could be mounted i

Re: [talk-au] new toy found by son

2009-10-01 Thread John Smith
2009/10/1 Elizabeth Dodd : >> The higher the gain the better the accuracy etc, most GPS antenna are >> tiny so if you make a massive one you should get good readings :) > because he wants a degree in surveying, that's why > so he has to produce something new / different Oh that's easy then, get h

Re: [talk-au] new toy found by son

2009-10-01 Thread b . schulz . 10
y, October 1, 2009 9:58 pm Subject: Re: [talk-au] new toy found by son To: Liz Cc: talk-au@openstreetmap.org > 2009/10/1 Liz : > > he was hoping that gps+accelerometers+gyros would provide > accurate cheap > > mapping of mtb trails > > Why not just build/buy a better anten

Re: [talk-au] new toy found by son

2009-10-01 Thread Elizabeth Dodd
On Thu, 1 Oct 2009, John Smith wrote: > 2009/10/1 Liz : > > he was hoping that gps+accelerometers+gyros would provide accurate cheap > > mapping of mtb trails > > Why not just build/buy a better antenna for the GPS? > > The higher the gain the better the accuracy etc, most GPS antenna are > tiny so

Re: [talk-au] new toy found by son

2009-10-01 Thread John Smith
2009/10/1 James Livingston : > On 01/10/2009, at 8:53 PM, John Smith wrote: >> I tried to use it to augment GPS data but the math ended up doing my >> head in so I'm not sure how much use this would be compared to a 4 or >> 5Hz GPS logger alone unless someone is super duper at velocity math >> that

Re: [talk-au] new toy found by son

2009-10-01 Thread John Smith
2009/10/1 Liz : > he was hoping that gps+accelerometers+gyros would provide accurate cheap > mapping of mtb trails Why not just build/buy a better antenna for the GPS? The higher the gain the better the accuracy etc, most GPS antenna are tiny so if you make a massive one you should get good readi

Re: [talk-au] new toy found by son

2009-10-01 Thread Liz
On Thu, 1 Oct 2009, James Livingston wrote: > On 01/10/2009, at 8:53 PM, John Smith wrote: > > I tried to use it to augment GPS data but the math ended up doing my > > head in so I'm not sure how much use this would be compared to a 4 or > > 5Hz GPS logger alone unless someone is super duper at vel

Re: [talk-au] new toy found by son

2009-10-01 Thread James Livingston
On 01/10/2009, at 8:53 PM, John Smith wrote: > I tried to use it to augment GPS data but the math ended up doing my > head in so I'm not sure how much use this would be compared to a 4 or > 5Hz GPS logger alone unless someone is super duper at velocity math > that is. It wouldn't be too hard, just

Re: [talk-au] new toy found by son

2009-10-01 Thread John Smith
2009/10/1 Liz : > http://www.sparkfun.com/commerce/product_info.php?products_id=8725 I've played with the accelerometer on the android handset I have, it can do 20 or 30 updates per second depending how busy the CPU is with other interupts. I tried to use it to augment GPS data but the math ended

[talk-au] new toy found by son

2009-10-01 Thread Liz
http://www.sparkfun.com/commerce/product_info.php?products_id=8725 ___ Talk-au mailing list Talk-au@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-au