Remote Raman measurements of minerals, organics, and inorganics at 430  m range

Abstract

Raman spectroscopy is a characterization technique that is able to analyze and detect water or water-bearing minerals, minerals, and organic materials that are of special interest for planetary science. Using a portable pulsed remote Raman system with a commercial 8 in. (203.2 mm) telescope, a frequency doubled Nd-YAG-pulsed laser, and a spectrometer equipped with an intensified CCD camera, we acquired good quality Raman spectra of various materials from a 430 m standoff distance during daylight with detection times of 1-10 s, in a realistic context in which both the exciting source and the detector are part of the same measurement system. Remote Raman spectra at this distance provided unambiguous detection of compounds such as water and water ice, dry ice, sulfur, sulfates, various minerals and organics, and atmospheric gases. This research work demonstrates significant improvement in the remote Raman technique as well as its suitability for solar system exploration.

Explosives sensing using Ag–Cu alloy nanoparticles synthesized by femtosecond laser ablation and irradiation

“…All the observed Raman peaks at 712, 1047 and 1362 cm À1 are well-matched with reported data from literature. 65,66 The peaks assignments are summarized in Table S1. † The main characteristic peak of 1047 cm À1 is assigned to NO 3 À stretch mode and the estimated EF for AN (5 mM) was $3.3 Â 10 4 .…”

Raman Spectroscopy from Laboratory and Proximal to Remote Sensing: A Tool for the Volcanological Sciences

“…More than 20 years ago, Angel et al [8] were able to identify organic and inorganic compounds on targets up to 20 m away. The coupling of the Raman system with a telescope in Cassegrain configuration is at present the most sensible configuration to reach big distances, up to hundreds of meters [56]. The coupling can be made by means of fiber optics or directly.…”

“…The main improvement has been the use of a pulsed laser as the excitation source, coupled to a time-gated charge coupled device (CCD) or, better, intensified CCD (iCCD), as detector [56]. The time resolution allows to acquire the signals only during the short time where the excitation is concentrated, reducing the interference of environmental light (allowing measurements in full daylight).…”

Standoff Raman spectroscopy for future Europa Lander missions

“…[19,20] In the case of a static lander or for fieldwork at the terrestrial Europa analog sites, the telescopic standoff Raman instrument mounted on a pan and tilt device offers the capability of mapping potential non-ice components over a wide area around the lander, with high spatial (≤1-cm diameter;~1.57-cm 2 area) resolution. [21][22][23][24] Telescopic standoff Raman systems have been used by Rull et al [25] for analyzing Arctic ice and by Bunkin et al [26] for remote sensing of sea water and drifting ice in Svalbard fjords. In the present work, we evaluate the performance of standoff Raman systems for detecting Europa-related non-ice components and chemicals placed at selected depths inside various types of H 2 O-ices.…”