Creating a Material Spectral Library for Plaster and Mortar Material Determination

Historic object analysis and the knowledge of composition play an important role in restoration processes. Based on this information, restoration works are conducted. This paper introduces a non-invasive technique of plaster and mortar material decomposition using reflectance spectroscopy. For this purpose, a NIRQuest512-2,5 from Ocean Optics®/Ocean Insight®, is used to create a unique spectral library consisting of various materials. They were carefully selected to include those that were and still are commonly used for a plaster and mortar production. Each material of the spectral library was mapped in detail, verified using scanning electronic microscope (SEM) data, and the results were compared to a previously determined spectral signature. The new spectral library was then tested on 11 unknown plaster and mortar samples and verified using a scanning electronic microscope. It was found that reflectance spectroscopy provides a powerful tool for plaster and mortar material decomposition, although at the moment it cannot fully replace invasive techniques like chemical analyses or other invasive techniques. It provides relevant information that can be used for restoration works.

Análise de dados de um espectrômetro óptico

Um espectrômetro óptico é um equipamento capaz de determinar as características de filmes finos, tais como espessura e constantes ópticas, pela sua interação com a luz. As constantes ópticas descrevem como a luz é refletida ou se propaga através de um material. Neste trabalho, utilizou-se um espectrômetro óptico portátil (Ocean Optics USB 4000), com o objetivo de analisar a curva de transmitância óptica em função do comprimento de onda de um filme fino de carbono amorfo hidrogenado. Esse filme possui alta transmitância na região próxima a 800 nm e baixa transmitância para comprimentos de onda abaixo de 400 nm. O índice de refração encontrado (ns) foi de 1,513, e a espessura do filme depositado (h), de 2.369 nm.

Light Scattering by Pure Water and Seawater: Recent Development

Light scattering by pure water and seawater is a fundamental optical property that plays a critical role in ocean optics and ocean color studies. We briefly review the theory of molecular scattering in liquid and electrolyte solutions and focus on the recent developments in modeling the effect of pressure, extending to extreme environments, and evaluating the effect of salinity on the depolarization ratio. We demonstrate how the modeling of seawater scattering can be applied to better understand spectral absorption and attenuation of pure water and seawater. We recommend future efforts should be directed at measuring the polarized components of scattering by pure water over a greater range of wavelengths, temperature, salinity, and pressure to constrain and validate the model and to improve our knowledge of the water’s depolarization ratio.

Experimental study on the use of unmanned aerial vehicles for the prediction of oil and gas facilities

The article is devoted to the topical problem of forecasting oil and gas promising objects using the latest remote sensing technologies. The proposed new approach to obtaining field verification data is an essential component of the methodology for solving oil and gas prospecting problems on land (satellite technology).Experimental field studies were carried out using the Ocean Optics STS-VIS Developers kit spectroradiometer installed on a quadcopter. Using the example of the Vostochnorogintsevska area, which is part of the Talalaevska-Rybaltsy oil and gas region of the Dnieper-Donetsk oil and gas region, the main stages of the developed method are demonstrated: a model of the fault-block structure was created, the neotectonic features of this area and its local blocks were estimated, photometric measurements of a multispectral satellite image along the route were carried out, birch leaves were sampled again along the same route for spectrometry using the ASD FieldSpec 3 FR instrument.The main objective of the experiment was to carry out field measurements with the Ocean Optics STS-VIS Developers kit spectroradiometer along a route that repeats the routes of measurements with spectrometers carried out earlier. The results showed that the optical anomaly, which is identified with a hydrocarbon accumulation, along the profile at the Vostochnorogintsevska area corresponds to the segment between points 15-26.The same anomaly has been established with the spectrometry device ASD FieldSpec 3 FR (2009 and 2021), the instrument SF-18 (1999 and 2004). Sufficiently accurately allocated transition from object to background, which corresponds to the boundary of the deposit on the drilling data (point 16 on the profile), i.e. has been confirmed in principle the possibility of allocating a low-intensity optical anomalies over hydrocarbon reservoirs using spectroradiometer STS-VIS Developers kit, mounted on quadrocopter.

Correction of Biogeochemical-Argo Radiometry for Sensor Temperature-Dependence and Drift: Protocols for a Delayed-Mode Quality Control

Measuring the underwater light field is a key mission of the international Biogeochemical-Argo program. Since 2012, 0–250 dbar profiles of downwelling irradiance at 380, 412 and 490 nm besides photosynthetically available radiation (PAR) have been acquired across the globe every 1 to 10 days. The resulting unprecedented amount of radiometric data has been previously quality-controlled for real-time distribution and ocean optics applications, yet some issues affecting the accuracy of measurements at depth have been identified such as changes in sensor dark responsiveness to ambient temperature, with time and according to the material used to build the instrument components. Here, we propose a quality-control procedure to solve these sensor issues to make Argo radiometry data available for delayed-mode distribution, with associated error estimation. The presented protocol requires the acquisition of ancillary radiometric measurements at the 1000 dbar parking depth and night-time profiles. A test on >10000 profiles from across the world revealed a quality-control success rate >90% for each band. The procedure shows similar performance in re-qualifying low radiometry values across diverse oceanic regions. We finally recommend, for future deployments, acquiring daily 1000 dbar measurements and one night profile per year, preferably during moonless nights and when the temperature range between the surface and 1000 dbar is the largest.

Instruments Operations, Science and Innovation in Expedition Support: EuroMoonMars-Etna campaign 2021

<p>An expedition EMM-Etna to simulate the Lunar and Martian volcanic and soil environment will be carried out at Mount.Etna’s Cratere del Laghetto in Sicily, near Catania Italy by the EuroMoonMars TUDublin and LEAPS ExoMars groups. This scouting campaign intends to train in using instruments to be used on MoonMars landers and rovers, with a perspective of ARCHES DLR telerobotics campaign to be conducted in June 2022, and in preparation for ExoMars rover instruments (PANCAM, CLUPI and spectrometers) science and operations.</p> <p> </p> <p> </p> <p> </p> <p>Figure 1: Lunar Lander and REMMI Rover for Sample Analysis</p> <p>The aim of this EMM-Etna expedition is to investigate and analyse the terrain with the use of different scientific instruments. The topography of the landscape will be photographed using a 360° panoramic camera and drone; it will be processed, and a 3D model developed. The terrain will also be investigated using the REMMI Rover, the abilities of the rover to operate and transport equipment will be monitored. This will further develop the knowledge available of the terrain and help future expeditions to identify different landmarks. The use of a Radio Jove Antenna will permit the team to monitor transmissions from both the Sun and Jupiter. This will allow different cosmic events or changes in the celestial objects to be studied and explored. On site a selection of different samples will also be collected and examined using the REMMI Rover. An Ocean Optics UV-Vis-NIR spectrometer will a be operated  in order to evaluate the existence of biological compounds and substances within these samples and in the area itself. It is key to understand the molecular makeup of one’s surroundings when in an unknown environment. By analysing samples collected, spectroscopy can be used to identify and determine a diagnostic for each substance. This process will be monitored by a Logitech camera to ensure it is carried put correctly. A selection of photographs will be captured of each sample using a portable optical microscope. This will allow an in-depth analysis of the microscopic structure of each collected sample. The use of all of the instruments mentioned above is key in the investigation and research into the Moon and Martian-like volcanic environment that is Mount Etna.</p> <p>We would also like to thank Prof I. Pagano's team from the University of Catania and Dr A.Wedler's team from DLR Deutsches Zentrum für Luft- und Raumfahrt for their support in organising this expedition.</p>

Spectral Relative Attenuation of Solar Radiation through a Skylight Focused on Preventive Conservation: Museo De L’almoina in Valencia (Spain) Case Study

The aim of the present study was to evaluate the relative attenuation of VIS, UV and NIR solar radiation through a large pond skylight into the interior of the l’Almoina Archaeological Museum (Valencia, Spain), and to determine how relative attenuation varied throughout the year and time of day. Measurements were taken at 9:00 a.m., 12:00 p.m. and 3:00 p.m. during July 2019 and January 2020. Relative attenuation values were obtained from the measurement of spectral irradiance in the exterior and at different points in the interior by means of two Ocean Optics spectrometers: HR4000CG-UV-NIR for VIS (400–700 nm) and NIR (700–1000 nm) bands, and FLAME-S-UV-VIS for UV-A (280–315 nm) and UV-A (315–400 nm) bands. The central points of the skylight had relative attenuation at 520 nm, reaching a value of 50% in summer at noon and 38% in the afternoon. At noon in winter, there were two relative attenuation peaks above 33% at 520 nm and at 900 nm. For mean relative attenuation, in the UVB range, the highest relative attenuation (20%) was inside the ruins in the morning in both summer and winter, and the UVA band relative attenuation was quite constant throughout the museum, but lower than that of the UVB band, in the range 0–3%.

Karakterisasi Sumber Cahaya Menggunakan Spektrofotometer Vis-Nir untuk Optimasi Optical Non-Contact Speedometer

Characterization the light source has been carried out using a Vis-Nir spectrophotometer with the Ocean Optics DTmini-2 model. The purpose of this characteristic is to obtain the optimum wavelength as a light source in making a digital optical non-contact speedometer model. There are 5 light sources tested, namely blue, green, yellow, red and white light. From the characterization results, the wavelengths were blue (450 nm), green (540 nm), yellow (570 nm), red (640 nm) and white (550 nm). In making the digital optical non-contact speedometer model, a photodiode sensor is used which has an absorbance peak point at 479 nm, 680, and 900 nm. The working principle of the prototype is to detect changes in light intensity as a result of the reflectance by the wheel. The sensor reads every color changes on the wheel and the results will be sent to the microcontroller for further processing. The results obtained are that the red LED is excellent to this prototype because it has the highest ADC value compared to other light sources tested. This is consistent with the results of the sensor spectrophotometer characterization.