IL NUOVO CIMENTO VOL. 15 C, N. 6 Novembre-Dicembre 1992 Multispectral Imaging of Mars: ISM Results (*). V. FORMISANO (1), G. BELLUCCI (1), A. GRIGORIEV(2), A. CORADIM(3) and J. P. BIBRING(4) (1) IFSI/CNR, Frascati, Italia (2) IKI, Moscow, USSR (3) IAS/CNR, Frascati, Italia (4) IAS/ CNRS, Orsay, France (ricevuto il 14 Luglio 1992) Summary. - Multispectral imaging of planets opens a new class of studies of atmospheric and surface signatures. With ISM experiment on board Phobos, the first IR multispectral imaging of Mars from space was achieved. In view of the future Omega experiment on board Mars 94, we present here a sample of data and results (and problems) which can be achieved by studying spectral reflectance. PACS 96.30 - Planets and satellites (excluding the Moon). 1. - Introduction ISM is an imaging spectrometer experiment working in the near-infrared spectral range ((0.8 -- 3.15) ttm covered with 128 bands) flown on board Phobos 1 and 2 missions to Mars. The description of the experiment in given in [1], here we remind the reader with some important experimental parameters. The spectral ranges (0.8- 1.6) and (1.6- 3.15) I~m are intrinsically separated as they are second-order and first-order spectrum respectively focused onto two 64-pixel PbS-cooled detectors. The instantaneous field of view was 12 arcmin wide, and imaging was obtained by means of a scanning mirror in one direction and by spacecraft motion in the other direction. Image cubes were therefore obtained which had + 20 ~ range cross track and as long as (1 000 -- 2 000) kin. Each cube is therefore 25 x 125 x 128, measurements corresponding to 400 x 3 000 km, (0.8- 3.15) pm spectrum. The entire mapping of Mars and Phobos was not (*) Paper presented atthe V Cosmic Physics National Conference, S. Miniato, November 27-30, 1990. 1113