inversion of radiometric measurements1

Abstract

Inversion of satellite radiometer measurements to yield values of atmospheric parameters is expected to be an important source of data within the next few years. A review of inversion methods, based in part on a recent workshop, is presented to outline their present status. General considerations indicate that fine structure will not be resolved, and that the number of parameters determined may be less than the number of measurements. Using infrared data, temperature profiles appear to be inferable with an accuracy of about ±3K, and water vapor distributions may be obtained, over clear skies or broken cloud. Microwave measurements appear to allow temperature determinations with similar accuracy which are less affected by underlying cloud. Water vapor and cloud liquid water content can also be determined, although there are engineering problems. Inversion of visible and ultraviolet data is not as far advanced, but may yield ozone distributions, cloud top heights and information on aerosols. A few of the present problem areas are mentioned.