[aprssig] barometric pressure units

Ian Wade G3NRW g3nrw-radio at ntlworld.com
Mon Nov 5 10:56:38 EST 2012

___Original Message_________________________________________
From: Steve Dimse <steve at dimse.com>
Date: Sun, 4 Nov 2012   Time: 22:18:37

>The baro pressure is 5 digits following lower case b, or 10150, which sure looks like Pa / 10 (or hPa x 10) to me.


Agreed. The reported barometric pressure is 1015.0 hectopascal, or 1015
millibars in old money.

I put the message through my APRSdec decoder, which reported thus:
Record #1
 APRS Data Type= Posit w/o time. No APRS
 Lat= 40 deg 02.66 min N  Long= 75 deg 27.34 min W
 Icon= WX station   Overlay= (none)
 Wind Direction= 319 deg   Speed= 002 knots (2.3 mph  3.7 kph  1.0 m/s)
 Gust Speed= 10 mph (16.1 kph  4.5 m/s  8.7 knots)
 Temp= 42 degF (5.6 degC)   Windchill= 42.1 degF (5.6 degC)
 Rain: Last hour= 0 in (0.0 mm)   Last 24 hrs= 0 in (0.0 mm)
       Since midnight= 0 in (0.0 mm)
 Humidity= 62 percent   Dew Point= 30.0 degF (-1.1 degC)
 Barometric Pressure= 1015 mbar/hP

APRSdec is at http://homepage.ntlworld.com/wadei/aprs.htm

On that page, click on the link "Demo output file" for many more
examples of its output.

I wrote the decoder 12 years ago, to help me verify the descriptions in
the APRS Specification. If anyone here knows of messages that do *not*
decode properly, please let me know. A lot has changed in the last 12

(You may also find the MIC encoder fun to play with, particularly if you
are a fixed station and you want to minimize message length).

Ian, G3NRW

The TS-590S Resources Page:






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