Pressure through GPS

Can I obtain pressure of that location from GPS NMEA format? If yes kindly, let me know how...

Thanks开发者_Python百科 Dheepak

Most devices do not have sensors to calculate barometric pressure. However, there are a few that do.

You should consult the documentation. Each device may have a specific proprietary sentence that it uses. For example: http://www.bohlken.net/download/nmeadata.pdf

$WIXDR,U,014.9,V,
$PXDR,1021.50,53534,-00.3,-01.1,-1530,1020.70
$WIXDR,P,1.0215,B,
$PXDR,1021.50,53535,-00.3,-01.1,-1560,1020.70
$WIXDR,C,+020,C,
$PXDR,1021.50,53535,-00.3,-01.1,-1590,1020.60
$WIXDR,U,014.9,V,
$PXDR,1021.50,53534,-00.3,-01.1,-1620,1020.40
$WIXDR,P,1.0215,B

you can't calculate pressure from gps data, because you have to know the current air pressure at the sea level at this place in this time and gps altitude is not very accurate. you have to use pressure sensor

I'm not sure if you can get air pressure from a nmea sentance. But you can always indirectly calculate it using this formula.

p = 101325 (1 - 2.25577 10^-5 h)^5.25588             

where

p = air pressure (Pa)

h = altitude above sea level (m) 

The altitude is available in the GPGGA sentance