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Error signal preventing
... sometimes, navigami gives a bad position, result of course, of a not valid satelitte signal...
...to prevent this, a function like "prevent signal satellite error" wich we could activate or not, and wich will not permit change cursor position if the position changes more than an (X) distance/altitude/speed in a second...
... if an error it´s detected, the current screen could show a message or a signal while it´s not corrected
... or we could establish a minimum number of satellites for the position is considered correct... and the cursor moved...
- By duartemelim at 10/27/2007 - 16:12
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Min Satellites...
Min Satellites available, to move cursor...
Max Speed...
Max Speed... smoothing...
max speed
write more please
Smoothing...
Menu Gps-Device-Smoothing- Min Speed and......
the cursor won´t be moved if:
- Max speed
(values higher than, for eg. 200km/h at a second)
- Min Satellites
(if there are only 3 or 2 satellites visible, cursor won´t be changed)
- Max altitude
(if altitude changes to many meters/km at a second)
...
This is just to prevent navigami to show bad positions, caused by gps errors, ... it´s like the Min Speed that you already have...
...sometimes our position moves, in a second, from a point to another many kms way, because of bad signal... if we have an item like "min speed" but with "max speed" the cursor won´t be moved, because the position moves to fast...
The altitude also, sometimes changes to "stupid" values...
In the future, every time "smoothing" is "activated" (data is filtred), could appear a symbol at the screen for we to know...
max speed Km/h - second...
max speed at the example ... 200 km/h = 55,555 mts second
200 000mts : 3600 seconds
second - every time gps position is refreshed
Navigami already discards invalid data
As far as I know, Navigami already discards data that is not valid.
Check the sats screen in navigami - you will only get a fix with at least 3 sats are shown in green
If you only have 2 or 3 sats visible, your GPS puts out data, but with an indicator that shows it is not valid - see
http://www.developerfusion.co.uk/show/4634/6/
Navigami will not display this position on the main screen, but will continue to show last known position. The direction arrow is white (unfilled) rather than black when this happens.
bad data
navigami does not filter bad data. it shows only data comming from your gps receiver. if trere are not enough satellites or signal is bad, the gps receiver does not send the position. bad data comes very rarely and you can filter it by yourself in most cases I think.
Good Signal / Bad Signal
Pherhaps for gps, 3 satellites are good, for me sometimes don´t...
specially when navigami gives me a position miles way, bad speed, bad altitude...
It´s because of that, i think navigami should filter more data, if we want.
Navigami is already filtering "bad data" when smooting.
The work of the gps, it´s giving´s a signal, most accuratly as possible, but unfortnely with some range of mistake. The work of the apllications is to give us that signal, preventing some mistakes that may occur... Our work it´s to use that information and analyse if it is correct, when we can... and hope that applications, filtres when we can´t...
filter
navigami filters only speed when smoothing. if speed < minspeed then speed = 0;
but I try to do something.
Smoothing if...
Smoothing
if speed > minspeed then speed = 0 (your eg. 3,6)
if speed > maxspeed then speed = 0 (150km - near the max we will use, better)
if satellites < minSatellites then speed = 0 (4 sat)
if altitudegps > maxaltitude then speed = 0 (18 000... i have seen this value one day... it´s because navigami is receiving bad data, i think it have to be filtered...)
Pherhaps smoothing stays better outside "Device"... if it have more settings...
yes navigami already discards data - 3D
the 2/3 Sattelites, was just an (bad) example. We could stablish other minimum: 4 or 5,... normaly we have more satellites...
good link ;)
The arrow turns black when it have no valid gps signal... but in the case of the "smoothing Min Speed" is still white...