PFS: an effective instrument for the study of martian environment

Abstract

We present here an evaluation of basic PFS sounding capabilities; results refer to the analysis of a single, calibrated spectrum. PFS is an infrared Fourier spectrometer on board of Mars Express mission. It covers the thermal infrared (250–1750 cm −1) with a resolution of 1.5 cm −1, as well as the near infrared (2000–8200 cm −1), with a resolution of 1.5 cm −1. It has been designed primarily to investigate the Martian atmosphere in its different cycles and interactions. This task can be achieved monitoring the fields of: (i) temperature (as a function of height) in the lower atmosphere, (ii) pressure, (iii) [H 2O], and optical thickness at different wavenumbers related to (iv) water ice and (v) dust integrated contents. The above mentioned parameters can be retrieved from a single PFS measurement, taking advantage of the instrument’s wide spectral range and high resolution. Specific retrieval software is under development in IFSI – CNR. Its performance is evaluated using as a reference a wide dataset of simulated PFS observations. The synthetic spectra have been computed taking into account likely environmental conditions (extracted from the European Martian Climate Database) and the actual instrument noise. We present here the general structure of the code; realistic estimates of errors on retrieved quantities are also provided. Special attention is devoted to the evaluation of T(p) profile. These preliminary results demonstrate the capability of PFS to achieve its general scientific objectives.