A Study of the Solar Radiation Effect on the 4.3-μm Channels of the High-Resolution Infrared Radiation Sounder

Abstract

Measurements of infrared radiation from the National Oceanic and Atmospheric Administration series of satellites are used to retrieve atmospheric temperature, moisture, and ozone. It is well known that the measurements from the 4.3-?m channels of the High-Resolution Infrared Radiation Sounder (HIRS) are affected by solar radiation. These effects can have an important effect on retrieved parameters and have caused difficulties in the use of the higher-peaking shortwave channels for many applications. In the channels that respond to the upper atmosphere, this effect can reach 2 K for high solar angles. In this paper, a regression procedure is used on nighttime data to determine a relationship between these channels and the other channels of the HIRS and the Microwave Sounding Unit of the Television and Infrared Operation Satellite Operational Vertical Sounder. This regression then is applied to daytime data to study the effect of solar radiation on these channels. This paper provides a method for estimating and partially removing these effects.