Current Trends in Spectral Reflectance Imaging Techniques: A Qualitative Approach to the Investigation and Documentation of Building Materials

Preservationists utilize many techniques to evaluate sites and monuments, and continually strive for increasing levels of accuracy. Today researchers are able to virtually reconstruct objects, buildings and entire sites through the use of digital-imaging technology, and many of these same techniques are being adapted to provide non-destructive documentation and material analysis. Increasing portability and decreasing cost of digital-imaging equipment promises to yield myriad avenues for investigation and provide further opportunities for accurate documentation. In consultation with imaging specialists and Columbia University faculty, a range of imaging techniques have been selected which represent potentially viable methods for non-destructive material analysis. Techniques of particular interest involve data collection within the visible and infrared regions of the electromagnetic spectrum, including thermographic-IR imaging, multispectral imaging, and hyperspectral imaging. By examining the materials associated with historic structures (e.g. stone, metal, brick, terra cotta, concrete and wood) and imaging technologies currently available, it is the goal of this research project to create a model for determining appropriate imaging techniques necessary to decipher construction materials. In doing so, this paper attempts to qualitatively examine the feasibility of using spectral-imaging for in-situ exterior survey and assessment of building facades, where it can be important to quickly, remotely and non-destructively distinguish among original construction, biological growth, paint, and other colored building materials

Optical tweezers in a dusty universe: Modeling optical forces for space tweezers applications

Optical tweezers are powerful tools based on focused laser beams. They are able to trap, manipulate, and investigate a wide range of microscopic and nanoscopic particles in different media, such as liquids, air, and vacuum. Key applications of this contactless technique have been developed in many fields. Despite this progress, optical trapping applications to planetary exploration are still to be developed. Here we describe how optical tweezers can be used to trap and characterize extraterrestrial particulate matter. In particular, we exploit light scattering theory in the T-matrix formalism to calculate radiation pressure and optical trapping properties of a variety of complex particles of astrophysical interest. Our results open perspectives in the investigation of extraterrestrial particles on our planet, in controlled laboratory experiments, aiming for space tweezers applications: optical tweezers used to trap and characterize dust particles in space or on planetary bodies surface

SuperCam Calibration Targets: Design and Development

SuperCam is a highly integrated remote-sensing instrumental suite for NASA’s Mars 2020 mission. It consists of a co-aligned combination of Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), Visible and Infrared Spectroscopy (VISIR), together with sound recording (MIC) and high-magnification imaging techniques (RMI). They provide information on the mineralogy, geochemistry and mineral context around the Perseverance Rover. The calibration of this complex suite is a major challenge. Not only does each technique require its own standards or references, their combination also introduces new requirements to obtain optimal scientific output. Elemental composition, molecular vibrational features, fluorescence, morphology and texture provide a full picture of the sample with spectral information that needs to be co-aligned, correlated, and individually calibrated. The resulting hardware includes different kinds of targets, each one covering different needs of the instrument. Standards for imaging calibration, geological samples for mineral identification and chemometric calculations or spectral references to calibrate and evaluate the health of the instrument, are all included in the SuperCam Calibration Target (SCCT). The system also includes a specifically designed assembly in which the samples are mounted. This hardware allows the targets to survive the harsh environmental conditions of the launch, cruise, landing and operation on Mars during the whole mission. Here we summarize the design, development, integration, verification and functional testing of the SCCT. This work includes some key results obtained to verify the scientific outcome of the SuperCam system

Reviewing in situ analytical techniques used to research Martian geochemistry: From the Viking Project to the MMX future mission

[EN] The study of space has always been a field of great interest and thus space missions are becoming more and more ambitious with time. Therefore, with the 50th anniversary of the first spacecraft to land on Mars, a review about how traditional analytical techniques have been adapted to the era of in situ space exploration is presented. From the Viking Project to the future MMX mission, the techniques used for the in situ study of the geochemistry of the Martian surface is described. These techniques have been differentiated according to the type of analysis: elemental and molecular. On the one hand, among the elemental analytical techniques the XRF, APXS, ISE and LIBS stand out. On the other hand, GCMS, TEGA, MBS, XRD, Raman and IR spectroscopy have been the molecular techniques used in the missions to Mars. Miniaturization, real-time measurements, automation, low power consumption and reliability of operation under extreme conditions are some of the major challenges that analytical chemistry has faced as a result of the technological and scientific requirements of space missions. In this way, this review gathers all the in situ analytical techniques that have reached the surface of Mars onboard landers or rovers with the aim of studying its geochemistry.J. Huidobro is grateful to the Basque Government for her pre-doctoral contract. J. Aramendia is grateful to the European Union's Horizon 2020 research and innovation programme under the Marie Skodowska-Curie grant agreement No. 754513 and the Aarhus University Research Foundation for her fellowship

Multispectral and Hyperspectral Remote Sensing Data for Mineral Exploration and Environmental Monitoring of Mined Areas

In recent decades, remote sensing technology has been incorporated in numerous mineral exploration projects in metallogenic provinces around the world. Multispectral and hyperspectral sensors play a significant role in affording unique data for mineral exploration and environmental hazard monitoring. This book covers the advances of remote sensing data processing algorithms in mineral exploration, and the technology can be used in monitoring and decision-making in relation to environmental mining hazard. This book presents state-of-the-art approaches on recent remote sensing and GIS-based mineral prospectivity modeling, offering excellent information to professional earth scientists, researchers, mineral exploration communities and mining companies

Development of innovative analytical methodologies, mainly focused on X-ray fluorescence spectrometry, to characterise building materials and their degradation processes based on the study performed in the historical building Punta Begoña Galleries (Getxo, Basque Country, Spain)

282 p.The characterisation and preservation of Cultural Heritage is of great importance in order to understand and preserve human evolution and history. Mortars are usually the main material employed in the construction of buildings belonging to Cultural Heritage. These building materials are multi-layered complex systems, often characterised by an inhomogeneous structure with a composition varying surprisingly depending on their geographical location and time period. The characterisation of the original composition and the definition of the degradation reactions of mortars can give assistance to restorers and can lead to propose new ways for future conservation (e.g. preventive conservation). In this PhD. Thesis, new Analytical Methodologies have been developed for the characterisation of mortars and the diagnosis of pathologies present on them, trying to encompass some of the most important facts present in the current evolution of the science dedicated to Cultural Heritage. Portable devices based on elemental and molecular spectroscopic techniques have been demonstrated as powerful tools to extract reliable conclusions without extracting any sample, which is of high importance when dealing with objects belonging to Cultural Heritage. On the one hand, different new easy and cost-effective natural and artificial passive samplers useful for the characterisation of the increasing atmospheric Particulate Matter in the current atmosphere are proposed in order to study the effect of its deposition over the building materials. On the other hand, the advantages of the increasing in situ non-destructive analytical techniques are also shown as well as the development of new X-ray fluorescence based quantification methodologies as an easy, cost effective and Green Analytical Chemistry option to other more traditionally employed techniques for the characterisation of building materials and their degradation products. At the time of starting the project of this PhD. Thesis, the University of the Basque Country UPV/EHU and the City Council of Getxo (Basque Country, Spain) signed an agreement to recover a highly degraded historical building, the Punta Begoña Galleries. The proposed methodologies have been developed based on the materials from this building and the degradation processes that are suffering