Active Topics
-
Extra softwares in Sailfish using CLI, repositories, etc (117)
to SailfishOS by nieldk - 3 hrs, 39 mins ago -
Firefox with Leste (6)
to Maemo 7 / Leste by teroyk - 1 day ago - more...
srydy |
2010-08-30
, 19:01
|
|
Posts: 8 |
Thanked: 0 times |
Joined on Aug 2010
|
#1
|
I called Nokia support and was told that N900 is not a real GPS device hence it requires an internet connection.
 |
|
2010-08-30
, 19:04
|
|
Posts: 658 |
Thanked: 117 times |
Joined on Jan 2010
|
#2
|
That's not true for sure. It just takes ages to get an sat-fix w/o a-GPS.
|
|
2010-08-30
, 19:06
|
|
Posts: 889 |
Thanked: 537 times |
Joined on Mar 2010
@ scotland
|
#3
|
i think we have assisted gps, it uses the internet to get a rough location, cutting down the time it takes to get a satellite connection since it knows where to look (i generally think 'up' is the correct direction to look for sattelites, but what do i know.)
__________________
sarcasm may be the lowest form of wit, but its the only wit i have.
its a sad day when i can't slip at least one hitchhiker reference in somewhere.
sarcasm may be the lowest form of wit, but its the only wit i have.
its a sad day when i can't slip at least one hitchhiker reference in somewhere.
 |
|
2010-08-30
, 19:08
|
|
Posts: 378 |
Thanked: 206 times |
Joined on Dec 2009
@ Denmark
|
#4
|
The nokia support is wrong in that statement. The n900 contains a real gps antenna.. however its weaker compared to car navigation devices gps antenna..
Therefor it uses what is called a-gps (assisted gps) and accesses internet to get information on where current gps salitelites are located in the sky, wich will help get a quicker gps fix.
Its possible to get a gps fix without internet, but it might take longer, and things like weather and buildings and such might have a big impact on how fast you get a fix.
Therefor it uses what is called a-gps (assisted gps) and accesses internet to get information on where current gps salitelites are located in the sky, wich will help get a quicker gps fix.
Its possible to get a gps fix without internet, but it might take longer, and things like weather and buildings and such might have a big impact on how fast you get a fix.
| The Following User Says Thank You to mthmob For This Useful Post: | ||
|
|
2010-08-30
, 21:51
|
|
Posts: 328 |
Thanked: 101 times |
Joined on Dec 2009
|
#5
|
Originally Posted by mthmob
Its possible to get a gps fix without internet, but it might take longer, and things like weather and buildings and such might have a big impact on how fast you get a fix.
This is the key. If you use the assisted gps using internet, it will help to get the current position within seconds rather than "minutes".
|
|
2010-08-30
, 22:53
|
|
Posts: 1,522 |
Thanked: 392 times |
Joined on Jul 2010
@ São Paulo, Brazil
|
#6
|
Why is it so hard to calculate where the satellites are with reasonable accuracy? If you know their position in a point in time it's just a mater of doing some math to get their position at any moment in the future (the far the two moments are the worse the accuracy is, but i wouldn't expect it to get too bad in just a couple of days, and whenever there is a connection to the internet it can re-zero the positions to a more accurate measurement.
|
|
2010-08-30
, 23:18
|
|
Posts: 726 |
Thanked: 345 times |
Joined on Apr 2010
@ Sweden
|
#7
|
Originally Posted by TiagoTiago
Are the satellites geostationary? If that's the case, you can't do any math to find them. Then you need to get some other fix, like using 2G/3G antennas.
Why is it so hard to calculate where the satellites are with reasonable accuracy? If you know their position in a point in time it's just a mater of doing some math to get their position at any moment in the future (the far the two moments are the worse the accuracy is, but i wouldn't expect it to get too bad in just a couple of days, and whenever there is a connection to the internet it can re-zero the positions to a more accurate measurement.
|
|
2010-08-30
, 23:22
|
|
Posts: 1,522 |
Thanked: 392 times |
Joined on Jul 2010
@ São Paulo, Brazil
|
#8
|
No, they spin around the earth in a spherical constellation all at pretty mucht he same altitude; it's fun to watch speed up animations of them going around trying to figure out the path of a single one, it's kinda an optical illusion, kinda looks like they will collide or make an extreme turn when reaching the poles.
|
|
2010-08-30
, 23:27
|
|
Posts: 130 |
Thanked: 51 times |
Joined on Sep 2009
|
#9
|
Originally Posted by TiagoTiago
I think the problem with this calculation is that the clock of the N900 would not be accurate enough. You can calculate the position of the sattelite, but you never know if your "now" is exactly the same as the sattelites "now".
Why is it so hard to calculate where the satellites are with reasonable accuracy? If you know their position in a point in time it's just a mater of doing some math to get their position at any moment in the future (the far the two moments are the worse the accuracy is, but i wouldn't expect it to get too bad in just a couple of days, and whenever there is a connection to the internet it can re-zero the positions to a more accurate measurement.
|
|
2010-08-30
, 23:37
|
|
Posts: 1,522 |
Thanked: 392 times |
Joined on Jul 2010
@ São Paulo, Brazil
|
#10
|
I wouldn't expect the error in the position would be big enough to make the result of the calculation useless.
btw, here is an animation of the satelites orbiting:
(in this one the effect i mentioned in my previous post isn't noticeable_
according to the source it says time is sped up 2880 times making one day go by in 30 seconds, and the time of a single orbit of a single satelite is 12 hours, i think those numbers would probably be enough to calculate how many degrees per minute the satellites move in the sky.
btw, here is an animation of the satelites orbiting:
(in this one the effect i mentioned in my previous post isn't noticeable_
according to the source it says time is sped up 2880 times making one day go by in 30 seconds, and the time of a single orbit of a single satelite is 12 hours, i think those numbers would probably be enough to calculate how many degrees per minute the satellites move in the sky.
| The Following User Says Thank You to TiagoTiago For This Useful Post: | ||