Barometric pressure

[ZUM]

How do AWOS/ASOS weather stations determine sea level pressure barometric pressure values? I've always been a little confused about this especially for high elevation airports like telluride, CO, which are able to report sea level pressure barometric pressures. Is the station pressure converted to sea level using the 1":1000' rule?
Thanks

 

[Screaming_Emu]

I'm not 100% sure on this, but I would assume they use the standard lapse rate to figure out what the pressure would be at sea level.

 

[FLY_CRJ]

Yes thats right Emu