Experimental and theoretical investigation on pressure-broadening and and pressure-shifting of the 22.2 GHz line of water

Since water is a fundamental component of the atmosphere and it is well established that the accuracy of collisional broadening parameters has a crucial influence on reduction of remote sensing data, we decided to investigate the self-, N2- and O2-broadening parameters of the J=6,1,6-5,2,3 (22.2 GHz) rotational transition of water in the temperature range 296–338 K. Due to the relevance of this water line, this investigation should be considered of particular interest in monitoring the Earth’s atmosphere, and therefore a particular effort has been made in order to reduce instrumental as well as systematic errors. Experimental determinations have also been supported by theoretical calculations.