Retrieving Water Vapor using GPS Technology - Demonstration Network

• A demonstration network of 55 GPS receivers has been installed largely in the central part of the country to "prove the concept"

• you may see GPS receivers at more than 800 ASOS sites around the country

• GPS measurements are converted into integrated precipitable water (IPW) measurements every 30 minutes

• Research with the RUC-2 model has shown that GPS IPW has improved forecasts when incorporated into the model