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The goal of this study was to investigate the performance of a spectral-transformation wave retrieval algorithm and confirm the accuracy of wave retrieval from C-band Chinese Gaofen-3 (GF-3) Synthetic Aperture Radar (SAR) images. More than 200 GF-3 SAR images of the coastal China Sea and the Japan Sea for dates from January to July 2020 were acquired in the Quad-Polarization Strip (QPS) mode. The images had a swath of 30 km and a spatial resolution of 8 m pixel size. They were processed to retrieve Significant Wave Height (SWH), which is simulated from a numerical wave model called Simulating WAves Nearshore (SWAN). The first-guess spectrum is essential to the accuracy of Synthetic Aperture Radar (SAR) wave spectrum retrieval. Therefore, we proposed a wave retrieval scheme combining the theocratic-based Max Planck Institute Algorithm (MPI), a Semi-Parametric Retrieval Algorithm (SPRA), and the Parameterized First-guess Spectrum Method (PFSM), in which a full wave-number spectrum and a non-empirical ocean spectrum proposed by Elfouhaily are applied. The PFSM can be driven using the wind speed without calculating the dominant wave phase speed. Wind speeds were retrieved using a Vertical-Vertical (VV) polarized geophysical model function C-SARMOD2. The proposed algorithm was implemented for all collected SAR images. A comparison of SAR-derived wind speeds with European Center for Medium-Range Weather Forecasts (ECMWF) ERA-5 data showed a 1.95 m/s Root-Mean-Squared Error (RMSE). The comparison of retrieved SWH with SWAN-simulated results demonstrated a 0.47 m RMSE, which is less than the 0.68 m RMSE of SWH when using the PFSM algorithm.

Inertial impactors are an important part of aerosol science where they are used to obtain particle size distributions in a wide range of practical and scientific applications. A shortcoming of thes...

The Interferometric Imaging Radar Altimeter (InIRA) is alow-orbit single-frequency altimeter whose signals are subject to an ionospheric delay, which introduces measurement errors. Additionally, so...

Evolution of fuel droplet evaporation zone and its interaction with the propagating flame front are studied in this work. A general theory is developed to describe the evolutions of flame propagation speed, flame temperature, droplet evaporation onset and completion locations in ignition and propagation of spherical flames. The influences of liquid droplet mass loading, heat exchange coefficient (or evaporation rate) and Lewis number on spherical spray flame ignition are studied. Two flame regimes are considered, i.e., heterogeneous and homogeneous flames, based on the mixture condition near the flame front. The results indicate that the spray flame trajectories are considerably affected by the ignition energy addition. The critical condition for successful ignition for the fuel-rich mixture is coincidence of inner and outer flame balls from igniting kernel and propagating flame. The flame balls always exist in homogeneous mixtures, indicating that ignition failure and critical successful events occur only in purely gaseous mixture. The fuel droplets have limited effects on minimum ignition energy, which however increases monotonically with the Lewis number. Moreover, flame kernel originates from heterogeneous mixtures due to the initially dispersed droplets near the spark. The evaporative heat loss in the burned and unburned zones of homogeneous and heterogeneous spray flames is also evaluated, and the results show that for the failed flame kernels, evaporative heat loss behind and before the flame front first increases and then decreases. The evaporative heat loss before the flame front generally increases, although non-monotonicity exists, when the flame is successfully ignited and propagate outwardly. For heterogeneous flames, the ratio of the heat loss from the burned zone to the total one decreases as the flame expands.

Using the cross-validation approach, strategies for estimating biophysical parameters are still pre-operational with synthetic aperture radar (SAR) data. In this regard, the Joint Experiment for Cr...

Spaceborne stripmap range sweep synthetic aperture radar (SS-RSSAR) can image regions of interest tilted with the satellite orbit and has great potential in reducing data rates and improving observ...

Spatiotemporal data fusion algorithms have been developed to fuse satellite imagery from sensors with different spatial and temporal resolutions and generate predicted imagery. In this study, we co...

A solar-powered tri-generation organic Rankine cycle (ORC) for generating electric power, producing fresh water, and providing heating power is proposed. Its performance is thermodynamically analys...

The influence of thermal radiation and Joule heating on the entropy inception by triple diffusion over the permeable plate is examined, as well as its influence on other physical aspects of the pro...

Eddy saturation describes the nonlinear mechanism in geophysical flows whereby, when average conditions are considered, direct forcing of the zonal flow increases the eddy kinetic energy, while the energy associated with the zonal flow does not increase. We present a minimal baroclinic model that exhibits complete eddy saturation. Starting from Phillips’ classical quasi-geostrophic two-level model on the beta channel of the mid-latitudes, we derive a reduced order model comprising of six ordinary differential equations including parameterised eddies. This model features two physically realisable steady state solutions, one a purely zonal flow and one where, additionally, finite eddy motions are present. As the baroclinic forcing in the form of diabatic heating is increased, the zonal solution loses stability and the eddy solution becomes attracting. After this bifurcation, the zonal components of the solution are independent of the baroclinic forcing, and the excess of heat in the low latitudes is efficiently transported northwards by finite eddies, in the spirit of baroclinic adjustment.

It is of great significance to accurately obtain the polar sea ice for the study of global hydrosphere and polar climate. The U-Net convolutional neural network (CNN) can achieve end-to-end pixel-l...

This study explores RAU-Net convolutional network architecture on satellite images by classifying geospatial objects on satellite images such as roofs to help in determining the building density of...

Quantitative Precipitation Forecast (QPF) obtained from a Numerical Weather Prediction model is used for streamflow forecasting. This study systematically evaluates the performance of a determinist...

Vehicle target recognition of synthetic aperture radar (SAR) is one of the critical tasks of image interpretation. Convolutional neural networks (CNNs) are increasingly used in SAR images and make ...

The assumption that the role atomic carbon is underestimated is made. The agreement with experimental data is shown.

An analysis of the scattering of steady-state SH waves by a shallow buried unlined elliptical tunnel is presented. For the horizontal boundary, a mirror method in elliptic coordinates is proposed, ...

Ozone is one of the key atmospheric trace gases that protects life on Earth from harmful solar ultraviolet radiation. The importance of ozone and its influence on various atmospheric processes led ...

We study a Sturm–Liouville problem in the cross-section of the ocean waveguide covered by pack ice. We prove the basis properties of the eigenfunctions, the convergence of the corresponding Fourier...

The processing of high resolution spotlight synthetic aperture radar (SAR) data suffers from Doppler spectrum aliasing because of the limited pulse repetition frequency (PRF). A modified two-step a...

This paper proposes an open sun drying (OSD) system for dried banana products using automatic dual-axis solar tracking. A pseudo-azimuthal mounting structure is implemented to rotate around the pri...

Ocean surface vector winds are of paramount importance for studying almost all meteorological and oceanographic processes. Wind vector products over the oceans are available from polar orbiting sca...

Measurements of vegetation greenness, such as those derived from spectral unmixing of satellite imagery using a greenness–darkness–brightness model, are crucial for improved mapping and analysis of...

Topological phase inversion, in which ��'-precipitate becomes topological matrix phase, is a typical ���detrimental��� microstructural degradation in Ni-based single-crystal superalloys. Here, a topologically inverse structure without service-induced damages is proposed. This structure exhibits excellent stress rupture properties at 1200��C and great microstructural stability, characterized by high, steady two-phase interface density. The relationship of the interface density to microscopic dislocation motion and macroscopic plastic deformation has been established, which reveals possible strengthening effect. These results will help understanding the benefit from this ���degraded��� but quite stable microstructure and guide microstructure tuning against long-termed heat-resisted service. Topological phase inversion achieved after heat treatment exhibits great microstructural stability and enhanced 1200��C stress rupture properties of single-crystal superalloys. The mechanism behind this beneficial effect is uncovered.

The localized forced ignition and subsequent flame propagation have been analyzed for stoichiometric biogas-air mixtures (CH4/CO2/air blend) with different spatial distributions (uniform, Gaussian ...

We consider a swelling porous-elastic system with a single nonlinear damping in the elastic equation. Recently, Ramos et al. [Stability results for elastic porous media swelling with nonlinear damp...

This paper sets out to simulate non-Gaussian wind speed time series. Given a set of historical wind speed observations, if the cumulative distribution function is not explicitly known, a probabilit...

This numerical study investigates supercritical carbon dioxide (s-CO2) as a medium for thermal energy storage (TES) systems operating under natural convection regarding heat transfer coefficient an...

Wind turbine systems exhibit highly nonlinear dynamics influenced by the aerodynamic torque induced in the wind turbine blades and thrust force on the turbine structure due to the wind flow. This p...

The surface dynamics of the rotating thermal convection are examined in finely resolved laboratory flows. Deep rotating convection creates geostrophic turbulent flow at the surface, the regime of c...

The soil roughness and two-way vegetation transmissivity parameters affect the radar backscattered signal; therefore, the results of the soil moisture retrieval from Synthetic Aperture Radar (SAR) ...

A three-dimensional model of an enclosed air-conditioned space was established. Numerical simulation was conducted for the temperature distribution in the enclosed space with the air conditioner tu...

This paper assesses thermoelastic damping (TED) in circular nanoplates by incorporation of the small-scale effect into structural and thermal domains. The nonlocal elasticity theory and dual-phase-...

The transportation sector is a major emitter of carbon dioxide emissions. It is a known fact that carbon dioxide is the cause of global warming which has resulted in extreme weather conditions as well as climate change. In this study a combination of different methods of expediting the CO2 emission from a single cylinder common rail direct injection (CRDI) engine has been explored. The methods include use of low carbon content biofuels (lemon peel oil (LPO) and camphor oil (CMO), inducing hydrogen in the intake manifold and zeolite based after-treatment system. Initial engine operation with the low carbon content biofuel blends resulted in reduced smoke and CO2 emissions. Substitution of the blends with hydrogen further assisted in decrease in emission and improvement in engine efficiency. Later on in the exhaust pipe an after-treatment system containing zeolite was placed. The emissions were found to reduce even further and at full load condition the lowest CO2 (39.7% reduction) and smoke (49% reduction) emissions were observed with LPO blend and hydrogen induction. The NO emission with hydrogen induction increases for both the blends, however, it was seen that the zeolite based treatment system was effective in reducing the emission as well. As compared to baseline diesel, the maximum reduction in NO emission was 23% at full load with LPO blend, hydrogen induction and after-treatment system. 2-s2.0-85114618706 WOS:000693966300001 Q2

This study is concerned with properties of freely propagating barotropic Rossby waves in a circular polar cap, a prototype model for the Arctic Ocean. The linearised shallow-water equations are use...

The results of the experimental studies of the particles ignition of bio-coal water fuels have been presented. The experiments have been carried out on the setup providing an error level of not mor...

In this study, copper/steel composite tubes were produced by an underwater explosive welding process. Scanning electron microscopy, energy dispersive spectroscopy, electron backscatter diffraction ...

The use of an axial dual-zone vortex chamber for spray drying applications is experimentally studied, focusing on water spray evaporation. In the hot zone of the vortex chamber, hot air (maximum 30...

A two-branch residual deep learning network is proposed for polarimetric synthetic aperture radar (PolSAR) image classification in this work. The proposed method integrates local information of pix...

A method to estimate nearshore bathymetry using SAR imagery is presented in this paper. A Fast-Fourier Transform (FFT) and Wavelet hybrid method is proposed to analyze the wave spectra and calculat...

In this paper, we qualitatively study the effect of the Coriolis force on traveling waves of the rotation-two-component Camassa–Holm system in the rotating fluid, which is a model in the equatorial...

We consider a one-dimensional thermoelastic Timoshenko system, where the heat conduction is given by Green and Naghdi theories and acting on shear force. We prove that the unique damping given by t...

A distributed multichannel synthetic aperture radar system refers to a multichannel synthetic aperture radar system with channels distributed and installed at different locations on the platform. I...

As a basic scattering element, arc-shaped structures can present considerable geometric information of the observed targets in synthetic aperture radar (SAR) images. The arc-shaped structures of va...

International audience; Industrial chimneys, launch vehicles and stacks are examples of large diameter circular cross section structures that can be prone to cross-wind vortex-induced vibration (VIV). VIV has been extensively studied for both fundamental and applied issues, but few documented studies concern high Reynolds number regimes (> 5 × 105) in atmospheric turbulent wind. This paper introduces a field test on a slender light and low damped chimney designed to experience “super-critical” VIV at moderate wind velocity. The chimney was recently erected in a wind monitored field, near the Atlantic coast of France. The purpose of this paper is to present the first vibration results obtained during a sequential 13-day period in September 2020. A statistical analysis has been performed on the amplitude and dominant frequency responses and results are reported in term of probability distribution as a function of wind speed and direction. VIV events of low (30% of diameter) have been highlighted in a range of wind velocity 25% lower than expected, along with significant influence of the wind direction – low turbulence easterly wind giving vortex-induced vibrations with the highest amplitude.

In this letter, a 4×6 microstrip patch array antenna with a low sidelobe level (SLL) for dual linearly polarized synthetic aperture radar (SAR) is proposed. The low SLL in wide-band is obtained by ...

Polar format algorithm (PFA) is an efficient image formation algorithm for spotlight-mode synthetic aperture radar (SAR). However, the derivation of PFA relies upon the approximation of planar wave...

In this study, we estimate the principal-agent model of moral hazard using a semi-parametric estimation method. We estimate the principal-agent model of moral hazard using longitudinal data on firm...

In the present paper, spatio-temporal variability in surface radiative energy fluxes has been estimated for snow/ice-covered Beas River basin, lower Western Himalaya, India using remote sensing tec...

Theoretically, the output power of a wind farm is mainly under influence of wind speed as an atmospheric parameter. However, there are other factors that impact wind power generation. Atmospheric s...

In this study, a high-speed imaging technique for recording spectral radiative images at high temporal–spatial resolutions were proposed to visualize the combustion process of a single coal particl...