Search results for "Spectral"

Spectrodirectional Minnaert-kretrieval using CHRIS-PROBA data

2010

We report on a detailed analysis of hyperspectral and multidirectional remote sensing data acquired using the Compact High Resolution Imaging Spectrometer (CHRIS) mounted onboard the Project for On-Board Autonomy (PROBA) spacecraft. This instrument is capable of sampling reflected radiation over the visible and near-infrared (NIR) region of the solar spectrum at a spatial resolution (approx. 17 m) intermediary between sensors traditionally used in land applications (such as Landsat and Satellite Pour l’Observation de la Terre (SPOT), 30 m–50 m) and the latest instruments delivering a nominal resolution of 1 m or less. The spectral anisotropic signature of an Alpine coniferous forest during …

Zeeman effect in sulfur monoxide: A tool to probe magnetic fields in star forming regions

2017

[Context] Magnetic fields play a fundamental role in star formation processes and the best method to evaluate their intensity is to measure the Zeeman effect of atomic and molecular lines. However, a direct measurement of the Zeeman spectral pattern from interstellar molecular species is challenging due to the high sensitivity and high spectral resolution required. So far, the Zeeman effect has been detected unambiguously in star forming regions for very few non-masing species, such as OH and CN.

Sevoflurane-induced reduction of bispectral index does not affect human cerebral microcirculation

2015

Using Matlab's wavelet toolbox to compare electric signals outputted by microbial fuel cells

2019

Motivation: microbial fuel cells (MFC) represents a wastewater treatment technology with the potential for a relevant electric energy generation. The monitoring of the electric current outputted generates time series of data. It was generated two time series using an experimental setup with a low-cost dual chamber microbial fuel cell treating cassava wastewater and, also, it was used the electric current data from a previously described experiment with this same setup treating cheese whey. All of this, innovatively, according our best knowledge, was studied using power spectral density, multifractal and wavelet coherence analysis. Results are promising and indeed point out this approach as …

Characterization of MEMS accelerometer self-noise by means of PSD and Allan Variance analysis

2017

In this paper, we have studied the sources of error of a low-cost 3-axis MEMS accelerometer by means of Power Spectral Density and Allan Variance techniques. These techniques were applied to the signals acquired from ten identical devices to characterize the variability of the sensor produced by the same manufacturer. Our analysis showed as identically produced accelerometer have somehow variable behavior in particular at low frequency. It is therefore of paramount importance before their use in Inertial Navigation or Earthquakes Monitoring System, a complete characterization of each single sensors.

Identification of microplastics using 4‐dimethylamino‐4′‐nitrostilbene solvatochromic fluorescence

2021

In this work, we introduce the use of 4-dimethylamino-4'-nitrostilbene (DANS) fluorescent dye for applications in the detection and analysis of microplastics, an impendent source of pollution made of synthetic organic polymers with a size varying from less than 5 mm to nanometer scale. The use of this dye revealed itself as a versatile, fast and sensitive tool for readily discriminate microplastics in water environment. The experimental evidences herein presented demonstrate that DANS efficiently absorbs into a variety of polymers constituting microplastics, and its solvatochromic properties lead to a positive shift of the fluorescence emission spectrum according to the polarity of the poly…

The Gaia-ESO Survey: Extracting diffuse interstellar bands from cool star spectra DIB-based interstellar medium line-of-sight structures at the kpc s…

2014

We study how diffuse interstellar bands (DIBs) measured toward distance-distributed target stars can be used to locate dense interstellar (IS) clouds in the Galaxy and probe a line-of-sight (LOS) kinematical structure, a potential useful tool when gaseous absorption lines are saturated or not available in the spectral range. Cool target stars are numerous enough for this purpose. We have devised automated DIB fitting methods appropriate to cool star spectra and multiple IS components. The data is fitted with a combination of a synthetic stellar spectrum, a synthetic telluric transmission, and empirical DIB profiles. In parallel, stellar distances and extinctions are estimated self-consisten…

Validation and comparison of two models based on the Mie theory to predict 8-14 µm emissivity spectra of mineral surfaces

2016

Benchmarking Saliency Detection Methods on Multimodal Image Data

2018

Saliency detecmage processing. Most of the work is adapted to the specific application and available dataset. The present work is about a comparative analysis of saliency detection for multimodal images dataset. There were many researches on the detection of saliency on several types of images, such as multispectral, natural, 3D and so on. This work presents a first focused study on saliency detection on multimodal images. Our database was extracted from acquisitions on cultural heritage wall paintings that contain four modalities UV, IR, Visible and fluorescence. In this paper, the analysis has been performed for many methods on saliency detection. We evaluate the performance of each metho…

An Embedded Solution for Multispectral Palmprint Recognition

2018

Palmprint based identification has attracted much attention in the past decades. In some real-life applications, portable personal authentication systems with high accuracy and speed efficiency are required. This paper presents an embedded palmprint recognition solution based on the multispectral image modality. We first develop an effective recognition algorithm by using partial least squares regression, then a FPGA prototype is implemented and optimized through high-level synthesis technique. The evaluation experiments demonstrate that the proposed system can achieve a higher recognition rate at a lower running cost comparing to the reference implementations.