Paola Manzari

The spectral imaging facility: Setup characterization

The SPectral IMager (SPIM) facility is a laboratory visible infrared spectrometer developed to support space borne observations of rocky bodies of the solar system. Currently, this laboratory setup is used to support the DAWN mission, which is in its journey towards the asteroid 1-Ceres, and to support the 2018 Exo-Mars mission in the spectral investigation of the Martian subsurface. The main part of this setup is an imaging spectrometer that is a spare of the DAWN visible infrared spectrometer. The spectrometer has been assembled and calibrated at Selex ES and then installed in the facility developed at the INAF-IAPS laboratory in Rome. The goal of SPIM is to collect data to build spectral libraries for the interpretation of the space borne and in situ hyperspectral measurements of planetary materials. Given its very high spatial resolution combined with the imaging capability, this instrument can also help in the detailed study of minerals and rocks. In this paper, the instrument setup is first described, and then a series of test measurements, aimed to the characterization of the main subsystems, are reported. In particular, laboratory tests have been performed concerning (i) the radiation sources, (ii) the reference targets, and (iii) linearity of detector response; the instrumental imaging artifacts have also been investigated.

Identification and classification of meteorites using a handheld LIBS instrument coupled with a fuzzy logic-based method

A handheld laser-induced breakdown spectroscopy (LIBS) instrument is proposed as a novel tool that is able to provide information on the nature of meteorites and discriminate among iron, stone, stony-iron meteorites and meteor-wrongs. Further, a novel fuzzy logic-based inference algorithm is applied to broadband LIBS spectra for the identification of meteorites and their classification according to their origin and nature. The identification of meteorites is a decision-making problem based on a compromise among human experience, visual evidence and analytical data, which fuzzy logic is proved to be able to solve. The final model is able to correctly classify 25 out of 26 samples and provides a set of IF-THEN rules that describe how some selected wavelengths are involved in the classification task.

Microimaging VIS-IR spectroscopy of ancient volcanic rocks as Mars analogues

The SPectral Imager (SPIM) facility is a laboratory VIS-IR spectrometer developed to support spaceborne observations of rocky bodies of the solar system. Currently, this laboratory setup is used to support the Dawn NASA mission and to support the 2018 ExoMars mission in the spectral investigation of Martian subsurface. Specifically, for this mission, a selection of relevant Mars analogue materials has been characterized and stored in the International Space Analogue Rockstore (ISAR), hosted in Orleans, France. In this investigation, two volcanic rock samples from the ISAR collection were analyzed. These two samples were chosen because of their similarity in mineralogical composition and age with Martian basalts and volcanic sands. Moreover, volcanic sands are particularly interesting because they can contain fossils of primitive life forms. The analysis of data collected by SPIM resulted in good agreement with the mineralogical phases detected in these two samples by mineralogical and petrographical techniques, demonstrating the effectiveness of the high spatial and spectral resolution of SPIM for identifying and for mapping different mineralogical species on cut rock and mineral samples.

The SPectral Imaging (SPIM) facility in support of hyperspectral observations of solar system bodies: Preliminary characterization

The SPectral IMaging (SPIM) facility is a laboratory imaging VIS-IR spectrometer, operative in the INAF/IAPS laboratory in Rome. The facility is used as a laboratory support for the DAWN mission (to the asteroids Vesta and Ceres) and for the 2018 ExoMars mission (to Mars). This imaging spectrometer, which is the spare of the VIR spectrometer [1,2] on-board the DAWN spacecraft, is operative in the 0.22–5.05 μm spectral range. It is characterized by high spatial (38 μm) and spectral (2 nm in the VIS channel, 12 nm in the IR channel) resolution. The high spectral performances, combined with the high spatial resolution imaging capability of this instrument allow a very accurate laboratory investigation and characterization of numerous types of mineral and rock samples, both in powder and in slab form, and also of extra-terrestrial samples, down to a few tens of micrometers in size.