Remote sensing of precipitable water by a thermal infrared multichannel approach

The paper describes a fast, simple algorithm for determining an assessment of the low-level tropospheric moisture content in clear air from measurements in three infrared water vapor window channels. The simple difference ratio in radiometric measurements is found to be linearly decreasing with atmospheric precipitable water. The retrieved precipitable water presents an rms deviation of 0.32 g/cm² with respect to closely coincident water vapor obtained by radiosonde.