From pointing measurements in stellar occultation to atmospheric temperature, pressure and density profiling: simulations and first GOMOS results

Abstract

In this work we consider the problem of determination of the stratospheric density and temperature profiles from the refractive-angle measurements. This study introduces new geophysical products, which can be obtained from the GOMOS instrument located on board the Envisat satellite. The procedure of temperature reconstruction consists of the following steps. First, the refractivity is reconstructed from the refractive angle measurements using the inversion of Abel-type integral. Refractivity is connected with air density via the Edlen formula. The pressure profile is calculated then using the hydrostatic equation. Finally, the temperature profile is determined from density and pressure data using the state equation of an ideal gas. The realistic error and analysis was performed. Sensitivity of the inversion procedure to the main error sources is studied. It is shown that both the sampling frequency and instrumental noise are very important for the reconstruction while the influence of scintillation effect and chromatic smoothing are negligible. The first results of density and temperature retrieval from the GOMOS measurements are presented.