Spectral Band Replication Compression Technology: Efficient Implementations of Complex Exponential- and Cosine-Modulated QMF Banks

Electro-optical parameters of fluorescein molecule in the second excited electronic state and information on the interactions with solvents were obtained from a solvatochromic study. Parameters of the solvents such as the refractive index, electrical permittivity and Kamlet-Taft parameters (hydrogen bond acidity and basicity) were related with the experimentally recorded shifts of UV absorption spectral band of fluorescein dissolved in several solvents. Through a variational method, the electric dipole moment and polarizability in excited state of fluorescein molecule were estimated. The calculus requires some parameters of the fluorescein molecule in the ground electronic state, which were determined through a quantum-mechanical study.

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Evaluation of the expediency of using thermal i magery data for decryption exogenous processes and vegetation

Geodesy and Cartography ◽

10.22389/0016-7126-2018-933-3-52-62 ◽

2018 ◽

Vol 933 (3) ◽

pp. 52-62

Author(s):

V.S. Tikunov ◽

I.A. Rylskiy ◽

S.B. Lukatzkiy

Keyword(s):

Spatial Data ◽

Laser Scanning ◽

Data Extraction ◽

Spectral Band ◽

Information Provision ◽

Lidar Data ◽

Thermal Imagery ◽

Scanning Lidar ◽

Field Works ◽

Object Features

Innovative methods of aerial surveys changed approaches to information provision of projecting dramatically in last years. Nowadays there are several methods pretending to be the most efficient for collecting geospatial data intended for projecting – airborne laser scanning (LIDAR) data, RGB aerial imagery (forming 3D pointclouds) and orthoimages. Thermal imagery is one of the additional methods that can be used for projecting. LIDAR data is precise, it allows us to measure relief even under the vegetation, or to collect laser re-flections from wires, metal constructions and poles. Precision and completeness of the DEM, produced from LIDAR data, allows to define relief microforms. Airborne imagery (visual spectrum) is very widespread and can be easily depicted. Thermal images are more strange and less widespread, they use different way of image forming, and spectral features of ob-jects can vary in specific ways. Either way, the additional spectral band can be useful for achieving additional spatial data and different object features, it can minimize field works. Here different aspects of thermal imagery are described in comparison with RGB (visual) images, LIDAR data and GIS layers. The attempt to estimate the feasibility of thermal imag-es for new data extraction is made.

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Spatiotemporal Fusion of Formosat-2 and Landsat-8 Satellite Images: A Comparison of “Super Resolution-Then-Blend” and “Blend-Then-Super Resolution” Approaches

Remote Sensing ◽

10.3390/rs13040606 ◽

2021 ◽

Vol 13 (4) ◽

pp. 606

Author(s):

Tee-Ann Teo ◽

Yu-Ju Fu

Keyword(s):

Satellite Images ◽

Traditional Approach ◽

Spectral Band ◽

Super Resolution ◽

High Temporal Resolution ◽

Landsat 8 ◽

Fusion Model ◽

Image Blending ◽

Fine Resolution

The spatiotemporal fusion technique has the advantages of generating time-series images with high-spatial and high-temporal resolution from coarse-resolution to fine-resolution images. A hybrid fusion method that integrates image blending (i.e., spatial and temporal adaptive reflectance fusion model, STARFM) and super-resolution (i.e., very deep super resolution, VDSR) techniques for the spatiotemporal fusion of 8 m Formosat-2 and 30 m Landsat-8 satellite images is proposed. Two different fusion approaches, namely Blend-then-Super-Resolution and Super-Resolution (SR)-then-Blend, were developed to improve the results of spatiotemporal fusion. The SR-then-Blend approach performs SR before image blending. The SR refines the image resampling stage on generating the same pixel-size of coarse- and fine-resolution images. The Blend-then-SR approach is aimed at refining the spatial details after image blending. Several quality indices were used to analyze the quality of the different fusion approaches. Experimental results showed that the performance of the hybrid method is slightly better than the traditional approach. Images obtained using SR-then-Blend are more similar to the real observed images compared with images acquired using Blend-then-SR. The overall mean bias of SR-then-Blend was 4% lower than Blend-then-SR, and nearly 3% improvement for overall standard deviation in SR-B. The VDSR technique reduces the systematic deviation in spectral band between Formosat-2 and Landsat-8 satellite images. The integration of STARFM and the VDSR model is useful for improving the quality of spatiotemporal fusion.

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Prediction performance optimization of different resolution and spectral band ranges for characterizing coco-peat substrate available nitrogen

Journal of Soils and Sediments ◽

10.1007/s11368-021-02949-4 ◽

2021 ◽

Author(s):

Bing Lu ◽

Xufeng Wang ◽

Nihong Liu ◽

Can Hu ◽

Jun Dong ◽

...

Keyword(s):

Performance Optimization ◽

Spectral Band ◽

Prediction Performance ◽

Available Nitrogen

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Study of a Current and Voltage Polarization Sensor Network

Sensors ◽

10.3390/s21134528 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4528

Author(s):

Artur de Araujo Silva ◽

Claudio Floridia ◽

Joao Batista Rosolem

Keyword(s):

Sensor Network ◽

Sensor Node ◽

Spectral Band ◽

Polarization Degree ◽

Pockels Effect ◽

Voltage Distribution ◽

Medium Voltage ◽

Voltage Sensors ◽

Polarization Sensor ◽

A Current

Sensors based on polarization are suitable for application in power grids due to their excellent characteristics, such as high electrical insulation, non-magnetic saturation, oil-free, no risk of explosive failures, and high bandwidth. Utility companies are incorporating new technologies that are driving the evolution of electrical systems. Thus, it is interesting to evaluate the possibility of using polarization sensors in a network configuration. In this work, we present an experimental study of a current and voltage polarization sensor network applied to a medium voltage distribution grid. The current sensor is based on the Faraday effect, and the voltage sensor uses the Pockels effect. Both sensors use a 90° polarization degree between the two output ports to compensate for the various impairments on the measurements by applying the difference-over-sum. The network uses a DWDM topology centered at the 1550 nm range, and both current and voltage sensors in this work used this spectral band. We evaluated the sensor node in terms of accuracy according to IEC standard 61869-10 and IEC standard 61869-11. Considering that an important application of this sensor network is in the aerial cable of medium voltage networks, sensor node accuracy was also estimated in the presence of cable vibration. The calculated power budget of the proposed network indicates that reaching ten nodes of current and voltage sensors in a 10 km optical link is possible, which is enough for a medium urban voltage distribution network.

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Hyperspectral Imagery for Assessing Laser-Induced Thermal State Change in Liver

Sensors ◽

10.3390/s21020643 ◽

2021 ◽

Vol 21 (2) ◽

pp. 643

Author(s):

Martina De Landro ◽

Ignacio Espíritu García-Molina ◽

Manuel Barberio ◽

Eric Felli ◽

Vincent Agnus ◽

...

Keyword(s):

Thermal Damage ◽

Thermal State ◽

Preliminary Investigation ◽

Spectral Band ◽

Spectral Variation ◽

Ablation Therapy ◽

Clinical Endpoints ◽

Breathing Motion ◽

Living Tissues

This work presents the potential of hyperspectral imaging (HSI) to monitor the thermal outcome of laser ablation therapy used for minimally invasive tumor removal. Our main goal is the establishment of indicators of the thermal damage of living tissues, which can be used to assess the effect of the procedure. These indicators rely on the spectral variation of temperature-dependent tissue chromophores, i.e., oxyhemoglobin, deoxyhemoglobin, methemoglobin, and water. Laser treatment was performed at specific temperature thresholds (from 60 to 110 °C) on in-vivo animal liver and was assessed with a hyperspectral camera (500–995 nm) during and after the treatment. The indicators were extracted from the hyperspectral images after the following processing steps: the breathing motion compensation and the spectral and spatial filtering, the selection of spectral bands corresponding to specific tissue chromophores, and the analysis of the areas under the curves for each spectral band. Results show that properly combining spectral information related to deoxyhemoglobin, methemoglobin, lipids, and water allows for the segmenting of different zones of the laser-induced thermal damage. This preliminary investigation provides indicators for describing the thermal state of the liver, which can be employed in the future as clinical endpoints of the procedure outcome.

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The Optical Properties of Leaf Structural Elements and Their Contribution to Photosynthetic Performance and Photoprotection

Plants ◽

10.3390/plants10071455 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1455

Author(s):

George Karabourniotis ◽

Georgios Liakopoulos ◽

Panagiota Bresta ◽

Dimosthenis Nikolopoulos

Keyword(s):

Glandular Trichomes ◽

Spectral Band ◽

Co2 Assimilation ◽

Photosynthetic Performance ◽

Structural Elements ◽

Internal Layers ◽

Water Losses ◽

Light Gradient ◽

Propagation Of Light ◽

Light Capture

Leaves have evolved to effectively harvest light, and, in parallel, to balance photosynthetic CO2 assimilation with water losses. At times, leaves must operate under light limiting conditions while at other instances (temporally distant or even within seconds), the same leaves must modulate light capture to avoid photoinhibition and achieve a uniform internal light gradient. The light-harvesting capacity and the photosynthetic performance of a given leaf are both determined by the organization and the properties of its structural elements, with some of these having evolved as adaptations to stressful environments. In this respect, the present review focuses on the optical roles of particular leaf structural elements (the light capture module) while integrating their involvement in other important functional modules. Superficial leaf tissues (epidermis including cuticle) and structures (epidermal appendages such as trichomes) play a crucial role against light interception. The epidermis, together with the cuticle, behaves as a reflector, as a selective UV filter and, in some cases, each epidermal cell acts as a lens focusing light to the interior. Non glandular trichomes reflect a considerable part of the solar radiation and absorb mainly in the UV spectral band. Mesophyll photosynthetic tissues and biominerals are involved in the efficient propagation of light within the mesophyll. Bundle sheath extensions and sclereids transfer light to internal layers of the mesophyll, particularly important in thick and compact leaves or in leaves with a flutter habit. All of the aforementioned structural elements have been typically optimized during evolution for multiple functions, thus offering adaptive advantages in challenging environments. Hence, each particular leaf design incorporates suitable optical traits advantageously and cost-effectively with the other fundamental functions of the leaf.

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