A Differential Absorption Model For Remote Sensing

Air pressure is one of the most important parameters regularly measured at surface meteorological stations. With developments of remote sensing methods, especially in airborne and satellite remote sensing techniques, large-scale and global surface pressure measurements significantly lag behind other important parameters, such as surface temperature. Researchers have suggested using satellite oxygen A-band methods (both passive and active) to measure the pressure. The active instruments rely on the operation of complicated highly stable laser systems on a space platform and are thus technically difficult, while passive methods are restricted to daytime measurements and areas of low cloud cover. Thus, there are still no real remote sensing measurements of surface pressure, even in experimental stages. This study considers active microwave techniques at strong O2 absorption bands (around 50–56-GHz) for the remote sensing of surface air pressure. At these frequencies, the total extinction of radar echoes from surfaces is strongly correlated with the amount of O2 in the atmosphere, atmospheric path lengths and surface air pressures.