Algorithm study on mid-infrared emissivity extraction from field measurements: A case study of soil

Based on the four step method, the paper puts forward a method for deriving mid-infrared emissivity. This method obtains thermal infrared emissivity and temperature with high accuracy by utilizing the ISSTES algorithm from thermal infrared data, then introducing the derived temperature into mid-infrared emissivity extraction, reducing the number of parameters need to be inversed in mid-infrared, forming redundant observation, and using the least square method to solve the equation at last. More attention has been paid into analyzing the impacts of instrument calibration error and simplification of radiative transfer equation on the extraction of mid-infrared emissivity. Finally, the paper gives out the reason for large error of emissivity inversion in some bands of mid-infrared based on the simulated data.