INFLUENCE OF NON-REPRESENTATIVE ATMOSPHERIC PROFILES ON ESTIMATES OF LAND-SURFACE TEMPERATURE BY MIVIS DATA USING RADIATIVE-TRANSFER MODELS

When retrieving ground surface temperatures from remote sensing images by a radiative transfer model, error's can arise from the use of atmo spheric vertical profiles that are not well representative of the imag ed area; due to non-local and/or non-simultaneous measurements. The ma gnitude of these errors is dependent on many factors such as the platf orm of the sensor (satellite or aircraft), the kind:of sensor (channel wavelength and band width) and the actual meteorological condition on the area. An evaluation of these errors is performed, both by means o f a simulation and by studying a real case using the data extracted fr om images acquired over Mt Etna (Sicily, southern Italy) by the MIVIS (Multispectral Infrared and Visible Imaging Spectrometer) airborne spe ctroradiometer during the 'Sicilia-94' remote sensing campaign. We mai nly connect the error in;surface temperature and the error in the colu mnar water vapor content caused by a non-representative profile. We sh ow that, in the case studied, these errors cannot be neglected; e.g., differences up to 5 degrees C in the most transparent channel (the oth er channels show greater values) are found. This work furnishes an imp ortant evaluation to the group working on the 'Sicilia-94' campaign an d,it may be useful for all the MIVIS users. Moreover, it makes possibl e comparison with other airborne TIR sensors like TIMS or ATLAS. Final ly, we think that this contribution may help to enhance the relation b etween land surface temperature/emissivity and atmospheric profile pro ducts as recommended at the International Land-Surface Temperature Wor kshop hold at the University of California. (C) 1998 Elsevier Science Ltd. All rights reserved.