The Simple Mono-Canal Algorithm for the Temperature Estimating of the Surface from Images of Infrared Thermal Canal of Meteosat
The knowledge of the surface temperature is strongly required in several applications, for instance in agrometeorology, climatology and environmental studies. In this study we have developed an algorithm mono-canal to estimate land surface temperature (Ts) in spectral band as the infrared channel (IR) of METEOSAT-7. This algorithm permits us to join by a relationship of second order the surface temperature to the brightness temperature (Tb) at the sensor level. This algorithm is obtained starting from the radiative transfer equation and requires the knowledge of atmospheric transmittance (t), the surface emissivity (e) and the effective mean atmospheric temperature (Ta). The results obtained were validated by using the LOWTRAN-7 radiative transfer code. For a values of atmospheric water content (W) lower or equal to 3.1 g/cm2 and for values of emissivity equal or higher than 0.98, we had found that the maximum difference between the land surface temperature estimated and simulated by LOWTRAN-7 does not exceed 2°C.
Keywords: land surface temperature, LOWTRAN-7, METEOSAT, algorithm mono-canal.