Comparison of column water vapor measurements using downward-looking near-infrared and infrared imaging systems and upward-looking microwave radiometers

Three sets of precipitable water vapor observations over the Front Range of eastern Colorado in March 1990 are compared. The remote-sounding techniques used are emission, reflectance, and microwave. Horizontal and temporal resolutions of the various instruments account for the small variations between data sets. The reflectance and microwave readings agreed to within 0.1 cm. and those of the latter had similar correlations with the radiosonde readings. Variable terrain within the satellite footprint accounted for differences of 0.4 and 0.5 cm. between emission and microwave data.