FEATURES OF CALIBRATION OF INFRARED RADIOMETERS WORKING IN WINDOW OF TRANSPARENCY OF THE ATMOSPHERE 8-14 MICRONS

Abstract

This article considers the possibility of using additional infrared radiometry compensators "transparent" in the operating spectral range of 8-14 μm and having radiating parameters controlled with high accuracy. This will allow a simpler way to register the radiation fluxes of the atmosphere at different zenithal angles without taking into account the hardware function of the radiometer. The constant monitoring of this function is quite a difficult technical task. It is proposed to use a polyethylene film with a thickness of 10 μm as a compensator. Depending on the value of the radiation flow, a certain number of layers of such a film with constantly controlled parameters, which will be a kind of a "reference radiator", are introduced into the measuring channel in front of the radiometer. The article presents theoretical calculations based on the laws of infrared radiation propagation in the Earth's atmosphere, as well as experimental data confirming the expediency of this technique in remote sensing of the atmosphere in the "transparency window". This technique extends the dynamic range of the radiometer in the low temperature range (below 223 K), which is the sensitivity threshold of most radiometers.The temperature of the "clean" atmosphere at the zenith is much lower.

Keywords

• atmosphere
• transparency window
• ir radiometer
• aerosol
• water vapor
• wavelength