ILAS (improved limb atmospheric spectrometer) ADEOA data retrieval algorithms

Data retrieval algorithms (version 1) have been developed for the Improved Limb Atmospheric Spectrometer (ILAS) project. The ILAS sensor is designed to measure atmospheric constituents and parameters with a solar occultation technique. Vertical profiles of temperature, pressure, and aerosol extinction coefficient are determined from visible channels covering the 753 similar to 784 nm wavelength range for O-2 molecular absorption. Profiles of O-3, CH4, N2O, HNO3, H2O, NO2, CFC-11, and aerosols are simultaneously obtained from IR channels (6.2 similar to 11.8 mu m wavelength range) with temperature and pressure profiles as already estimated, The retrieval is realized by vertical inversion with non-linear spectral fitting for each height. A numerical simulation test revealed that each target parameter (pressure, temperature, aerosol, and gas concentrations) can be retrieved by these algorithms to well within required precisions. (C) 1998 COSPAR. Published by Elsevier Science Ltd.