Argonne National Laboratory
The G-band vapor radiometer profiler (GVRP) provides time-series measurements of brightness temperatures from 15 channels between 170 and 183.31 GHz. Atmospheric emission in this spectral region is primarily due to water vapor, with some influence from liquid water. The wing channels between 170 and 175 GHz have sensitivity to the presence of liquid water. The sensitivity to water vapor of the 183.31-GHz line is approximately 30 times higher than at the frequencies of the two-channel microwave radiometer (MWR) for a precipitable water vapor (PWV) amount of less than 2.5 mm. Measurements from this instrument are especially useful during low-humidity conditions (PWV < 5 mm).