Method for Determining Atmospheric Aerosol Optical Depth Using Solar Transmission Measurements

A multiple wavelength radiometer instrumentation has been developed and used to measure solar irradiance in a water vapor absorption band in the near-infrared region. From these measurements the total atmospheric optical depth at each wavelength of observation is deduced using a linear least-squares fitting method. An iteration technique, based on a power law wavelength dependence of aerosol optical depth, is employed to retrieve aerosol optical depth from the total optical depth data. The technique permits simultaneous determination of precipitable water vapor amount