Several procedures have been developed to support the strategy for the remote sensing of Mars with the experiment Planetary Fourier Spectrometer (PFS) on board of Mars Express. The instrument is a dual channel Infrared Fourier spectrometer, always pointing to nadir down to the planet, with the possibility of shifting from the nadir pointing by +/-12.5degrees, +/-25degrees perpendicularly to the ground track direction. Among these procedures, the Mars Express Simulator has been implemented in order to obtain useful information about the position of the spot traced by the PFS on Mars. This tool has provided the possibility to plan limb observations in some particular conditions, reflectance phase function measurements, global coverage, local time coverage and so on. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.