Estimation of Precipitable Water Using Thermal Infrared Images

Abstract

Atmospheric water vapor is an important greenhouse gas, mainly distributed in the lower tropospheric levels where its concentration varies significantly in space and time; consequently, so does precipitable water. This work uses information from thermal infrared images to model precipitable water (PW) under clear skies. PW is measured using a portable sun-photometer and thermal images obtained through a high-cost thermal infrared camera. PW depends on the zenith-point temperature (Tb) exhibiting a non-linear positive exponential relationship, with systematic and dispersion errors of 0.04 mm and 1.9 mm.

Keywords

• precipitable water
• zenith-sky temperature
• sun-photometer
• thermal infrared images
• non-linear regression