- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[Advances in Intelligent Systems and Computing] Advanced Computing and Systems for Security Volume 883 (Volume Eight) || Remote Sensing Technology for Evaluation of Variations in Land Surface Temperature, and Case Study Analysis from Southwest Nigeria
摘要： Recent studies have shown that evaluation of the changes in the Land Surface Temperature (LST) of any area can be a re?ector of changes in urbanisation trend, industrial activities, population change and natural factors. Subsequently, many researches have evolved over time, especially with development in remote sensing, digital image processing and geographical information systems. This chapter is aimed at providing information on the relevance and challenges of remote sensing as a geospatial technology that is capable of being used for monitoring LST at different spatial and timescales. The case study analysis indicated that the results from the remote sensing processing of the imageries re?ect signi?cant in?uence of the spatial resolutions of selected imageries. The challenges of huge image data gaps, cloud cover, coarse spatial and temporal resolution, limited night-time data for evaluation of night-time urban heat island—for both technical and security reasons, in?uenced the reliability of the study results. The study recommended policies for improvement in the applications and utilisation of the geospatial technology in many developing countries, including Nigeria based on its strengths.
关键词： Nigeria,Image sensors,Land surface temperature,Image analysis
更新于2025-09-23 15:22:29
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - A Simple Fusion Approach of Chlorophyll Images and Sea Surface Temperature Images for Improving the Detection of Moroccan Coastal Upwelling
摘要： In order to improve the decision-making on the Moroccan upwelling region detection, we present in this paper a simple and reliable fusion approach. In this context, we started by applying Fuzzy C-means algorithm on each 46 Sea Surface Chlorophyll images and on each 46 Sea Surface Temperature images during the year of 2014. After that, we implement post classification fusion by using logical AND operator set to combine FCM result of the both types and consequently having single image more informative and suitable for visual perception. The oceanographer validation indicate that the proposed methodology detect automatically and effectively the different Moroccan coastal upwelling scenarios of our database.
关键词： Moroccan Coastal Upwelling,Fuzzy C-means,Sea Surface Temperature Image,Sea Surface Chlorophyll Image,Post Classification Fusion
更新于2025-09-23 15:21:01
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Estimation of 1-Km All-Weather Land Surface Temperature Over the Tibetan Plateau
摘要： Land surface temperature (LST) immensely affects the energy balance and water cycle on the earth’s surface. Merging thermal infrared (TIR) and passive microwave (MW) remote sensing provides the possibility to obtain all-weather LST with moderate resolutions. However, due to difficulties in downscaling MW LST, current methods merging TIR LST and MW LST into such an all-weather LST are limited over large areas with very complicated land surfaces (e.g. the Tibetan Plateau). By fully considering the influence of the topography on estimation of merged LSTs, this study revises the recently-developed physical method for generating the 1-km all-weather LST and applies it over the Tibetan Plateau to merge MODIS (1 km) and AMSR2 (10 km) observations. Results show that the merged LST has accuracy of 0.99 K-3.22 K when validated against in-situ LSTs from five ground stations with various land cover types. This study would be beneficial for continuously monitoring LST and improving spatio-temporal resolutions for associated land surface process studies requiring high-quality all-weather LST over large scales.
关键词： MODIS,Spatial correlations,AMSR2,Land surface temperature (LST),Passive microwave remote sensing
更新于2025-09-23 15:21:01
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Heat-induced Active Centers in Bismuth-doped Optical Fibers for 1.7-?μm-region Laser Applications
摘要： Satellite remote-sensing data and glider data are used to study the Kuroshio meander and surface properties, east of Taiwan. The Kuroshio meandered eastward 13 times between 1993 and 2013 because of cold eddies propagating from the western Pacific. The maximum duration of the meanders was 80 days. The farthest eastward shift of the Kuroshio axis was approximately 270 km from its original position, depending on the size of the cold eddy. Cold eddies reduce the current speed at the Kuroshio axis to 84% of its seasonal average, which is approximately 0.75 m/s. According to glider data, isopycnal uplifting is produced when cold eddies impinge on the Kuroshio, and satellite observations show that the sea surface temperature (SST) drops 1?3 ?C and that the chlorophyll-a (chl-a) concentration increases up to 0.54 mg/m3.
关键词： cold eddy,sea surface temperature (SST),Chlorophyll-a (chl-a),kuroshio meander
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE SENSORS - Montreal, QC, Canada (2019.10.27-2019.10.30)] 2019 IEEE SENSORS - Evanescent field waveguide particle detector : Simulations concerning size and shape dependence
摘要： The midinfrared (MIR) spectral region (3–5 μm), which penetrates most haze layers in the atmosphere and is less sensitive to variations in atmospheric water vapor, seems to be appropriate for retrieving land surface temperature (LST). However, there are currently few studies of LST retrieval with MIR data because it is difficult to eliminate solar irradiance from the total energy measured in the MIR during the daytime. This paper proposes a physics-based method to retrieve LST from MODIS daytime MIR data. The bidirectional reflectivity describing the reflected solar direct irradiance is determined using the method by Tang and Li. The directional emissivity, representing the surface emitted radiance, is determined by a kernel-driven bidirectional reflectance distribution function model, i.e., RossThick-LiSparse-R. Intercomparisons using the MODIS-derived LST product MYD11_L2, for the Baotou experimental site in Urad Qianqi, Inner Mongolia, China, have a maximum root-mean-square error (RMSE) of 1.69 K and a minimum RMSE of 1.31 K, for four scenes of MODIS images. Furthermore, in situ LSTs measured at the Hailar field site in northeastern Inner Mongolia, China, were also used to validate the proposed method. Comparisons of the LSTs retrieved from MODIS daytime MIR data and those calculated using in situ measurements have a bias and RMSE of ?0.17 K and 1.42 K, respectively, which indicates that the proposed method can accurately retrieve LST from MODIS daytime MIR data.
关键词： MODIS,midinfrared (MIR),Daytime,land surface temperature (LST)
更新于2025-09-23 15:19:57
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Infrared radiation characteristics of a hypersonic vehicle under time-varying angles of attack
摘要： Hypersonic vehicles emit strong infrared (IR) radiation signatures that can be treated as a detecting source for object identification and routine diagnosis. This paper is aimed at examining the intrinsic radiation characteristics of a Boost-Glide Vehicle (BGV) under the condition of various Angles of Attack (AOAs). A two-temperature model considering the thermal and chemical non-equilibrium effects is coupled with Navier-Stokes equations solved by the finite volume technique. A gas-solid conjunction heat transfer model is also added into the fluid solver to simulate the surface temperature of the vehicle. The radiative transfer equation is solved with Line of Sight (LOS) algorithm. The computational results for a Hypersonic Technology Vehicle-2 (HTV-2) type vehicle show that radiances of the vehicle are strongly dependent on the surface temperature. The presence of AOA results in the significant difference of the surface temperature. Infrared radiation characteristics are also changed in intensity and spectral band due to the AOA. Simulations are performed with two time-varying AOAs. Transient results indicate that the variation of AOA does have a great effect on the infrared radiance and is closely related to observation angle, spectral band, angle size, angular velocity and time history.
关键词： IR radiation,HTV-2,Surface temperature,Hypersonic vehicle,Fluid-thermal interaction,Angle of attack
更新于2025-09-19 17:15:36
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[IEEE 2019 Photonics North (PN) - Quebec City, QC, Canada (2019.5.21-2019.5.23)] 2019 Photonics North (PN) - Real-time Optical Beam Steering for Laser-Powered Epiretinal Prostheses
摘要： We propose a new deterministic approach for remote sensing retrieval, called modified total least squares (MTLS), built upon the total least squares (TLS) technique. MTLS implicitly determines the optimal regularization strength to be applied to the normal equation first-order Newtonian retrieval using all of the noise terms embedded in the residual vector. The TLS technique does not include any constraint to prevent noise enhancement in the state space parameters from the existing noise in measurement space for an inversion with an ill-conditioned Jacobian. To stabilize the noise propagation into parameter space, we introduce an additional empirically derived regularization proportional to the logarithm of the condition number of the Jacobian and inversely proportional to the L2-norm of the residual vector. The derivation, operational advantages and use of the MTLS method are demonstrated by retrieving sea surface temperature from GOES-13 satellite measurements. An analytic equation is derived for the total retrieval error, and is shown to agree well with the observed error. This can also serve as a quality indicator for pixel-level retrievals. We also introduce additional tests from the MTLS solutions to identify contaminated pixels due to residual clouds, error in the water vapor profile and aerosols. Comparison of the performances of our new and other methods, namely, optimal estimation and regression-based retrieval, is performed to understand the relative prospects and problems associated with these methods. This was done using operational match-ups for 42 months of data, and demonstrates a relatively superior temporally consistent performance of the MTLS technique.
关键词： ill-conditioned inverse methods,regularization,total error,total least squares (TLS),sea surface temperature (SST),Condition number of matrix,satellite remote sensing
更新于2025-09-19 17:13:59
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Laser-induced control of a cavity bubble behind a sinking sphere in water entry: Dependency on the surface temperature and impact velocity
摘要： We investigate the effect of continuous-wave laser irradiation on the cavity evolution behind a sphere in water entry. By tuning the irradiation time, the surface temperature (Ts) of the sphere before the impact varies in 105–355 ○C. We change the radius and impact velocity of the sphere, by which both the shallow and deep seals are considered. Compared to the reference case (the sphere was roughened to have a cavity initially), we find that the cavity expands or shrinks depending on Ts. Overall, for all cases, the cavity bubble expands to the maximum size and shrinks steeply with increasing Ts. At higher Ts, the cavity is destroyed significantly, even smaller than the reference case. However, the detailed interaction between the cavity and laser-induced cavitation bubbles is quite different. In a shallow-seal case, nucleate boiling occurs on the sphere surface and vapor bubbles merge into the cavity, resulting in the expansion of the cavity. At a highly subcooled condition, on the other hand, the vapor bubble collapses into microbubbles as soon as it contacts water, resulting in the cavity reduction. As the impact speed increases (for a deep-seal condition), the flux of entrained air becomes dominant and the stage of cavity expansion is quite narrow. As Ts increases, the heated cavity collapses into microbubbles and almost 90% is destroyed. Finally, we investigate the effects of modified cavity on hydrodynamic forces on the sphere. While the temporal variation of hydrodynamic forces is complex, the drag reduction over 40% is achieved.
关键词： cavity bubble,laser-induced control,impact velocity,water entry,surface temperature
更新于2025-09-16 10:30:52
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Effect of Laser Process Parameters on Laser Assisted Machining Of Inconel 718: Statistical – Regression Analyses
摘要： This paper discusses the effect of laser-assisted process parameters on cutting forces and surface temperature during laser assisted machining (LAM) of Inconel 718. The heat source used for pre-heating the surface is Nd:YAG laser source. Cutting speed, feed rate and laser power are the process parameter assessor for cutting force and cutting temperature. The experiments are planned and results are collected based on Taguchi’s L27 orthogonal design. The factor effect on output responses are analysed using a main effect plots (2D) and its significance is perceived from analysis of variance (ANOVA). Results reveal that cutting speed bags a maximum contribution of 56%, followed by cutting speed * feed rate as 24%, feed rate * laser power as 10.5 % and feed rate as 10%. Finally, the benefit of LAM was shown by 55% decrease in feed force (Fx), 50% decrease in thrust force (Fy) and 60% decrease in cutting force (Fz), as compared to those of the conventional machining. Additionally, it is also recommended to employ a work surface temperature in the range of 750?C–887?C during LAM of this Inconel 718 alloy to have maximum process benefits. The developed regression model reveals the goodness of fit with experimental data has high determination coefficient i.e. R2 = 0.91 for tangential force and 0.71 for surface temperature.
关键词： regression analysis,Statistical analysi,cutting forces,surface temperature
更新于2025-09-16 10:30:52
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[IEEE IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society - Lisbon, Portugal (2019.10.14-2019.10.17)] IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society - Analysis and Characterization of Factors Influencing the Energy Performance of Photovoltaic Systems
摘要： Satellite remote-sensing data and glider data are used to study the Kuroshio meander and surface properties, east of Taiwan. The Kuroshio meandered eastward 13 times between 1993 and 2013 because of cold eddies propagating from the western Pacific. The maximum duration of the meanders was 80 days. The farthest eastward shift of the Kuroshio axis was approximately 270 km from its original position, depending on the size of the cold eddy. Cold eddies reduce the current speed at the Kuroshio axis to 84% of its seasonal average, which is approximately 0.75 m/s. According to glider data, isopycnal uplifting is produced when cold eddies impinge on the Kuroshio, and satellite observations show that the sea surface temperature (SST) drops 1?3 ?C and that the chlorophyll-a (chl-a) concentration increases up to 0.54 mg/m3.
关键词： cold eddy,sea surface temperature (SST),Chlorophyll-a (chl-a),kuroshio meander
更新于2025-09-16 10:30:52