I contacted WeatherCloud support requesting what barometric pressure they desire to be uploaded to them from our pws. They stated “compensated barometric pressure”. How does this term fit into altimeter and sea level pressure? My guess is sea level pressure.
Ron.
Altimeter and barometric pressure in this case when we have atmosheric pressure sensore readings, both are sea level pressure reduction algorithms.
Barometer pressure is quite complicated. It takes not only elevation, but also temperature, humidity and dew point.
Altimeter needs only elevation.
There is more than one alghoritm for sea level reduction.
Please check here:
www.softwx.com // formulas/algorithms
// Sea Level Pressure reduction algorithms
TSLPAlgorithm = (
paDavisVP, // algorithm closely approximates SLP calculation used inside Davis Vantage Pro weather equipment console (http://www.davisnet.com/weather/)
paUnivie, // http://www.univie.ac.at/IMG-Wien/daquamap/Parametergencom.html
paManBar // from Manual of Barometry (1963)
);
// Altimeter algorithms
TAltimeterAlgorithm = (
aaASOS, // formula described in the ASOS training docs
aaASOS2, // metric formula that was likely used to derive the aaASOS formula
aaMADIS, // apparently the formula used by the MADIS system
aaNOAA, // essentially the same as aaSMT with any result differences caused by unit conversion rounding error and geometric vs. geopotential elevation
aaWOB, // Weather Observation Handbook (algorithm similar to aaASOS & aaASOS2 - main differences being precision of constants used)
aaSMT // Smithsonian Meteorological Tables (1963)
);
TVapAlgorithm = (
vaDavisVp, // algorithm closely approximates calculation used by Davis Vantage Pro weather stations and software
vaBuck, // this and the remaining algorithms described at http://cires.colorado.edu/~voemel/vp.html
vaBuck81,
vaBolton,
vaTetenNWS,
vaTetenMurray,
vaTeten
);
But, CWOP needs altimeter value. It has to be done.
Same problem I had on the beginning with coordinates. They use not very popular standard to describe longitude/latitude.
I hope that now WiFiLoggers will deliver proper data to CWOP.