Edinburgh Duck wave energy converter(ED WEC)has excellent energy extraction performance and shows a great potential to integrate with other marine structures.This paper aims to investigate its wave energy extraction p...Edinburgh Duck wave energy converter(ED WEC)has excellent energy extraction performance and shows a great potential to integrate with other marine structures.This paper aims to investigate its wave energy extraction performance as a WEC and wave attenuation performance as a protection method for shoreline or marine structures.The wave and ED WEC interactions in regular waves are modeled using the Star-CCM+software and verified by comparisons with published experimental results.The motion response,energy conversion efficiency,and transmission coefficient of the ED WEC with different attack angles,rotation center,and incident wave heights are investigated.Results indicate that the ED WEC with an attack angle of 42°and a rotation center of 0.55 m below the mean water line can achieve both good wave energy extraction and wave attenuation performances.The wave energy extraction and wave attenuation performance of the ED WEC decrease significantly with the increase of wave nonlinearity characterized by the wave steepness.This paper can guide the practical application of the ED WEC at the early stage of design.展开更多
Installing the Edinburgh Duck Wave Energy Converter(ED WEC)on a floating breakwater provides a potential solution to reduce costs and improve the reliability of the ED WEC.To investigate the interactions between the E...Installing the Edinburgh Duck Wave Energy Converter(ED WEC)on a floating breakwater provides a potential solution to reduce costs and improve the reliability of the ED WEC.To investigate the interactions between the ED WEC and the breakwater,a two-dimensional numerical model of a hybrid WEC-breakwater system is established based on Star-CCM+Computational Fluid Dynamics(CFD)software.The wave energy extraction performance,wave attenuation performance,and wave forces on the breakwater of the hybrid system are compared with those of the corresponding single device.The effects of the initial attack angle,the distance between the WEC and the breakwater,and the incident wave height on the pitch motion,energy conversion efficiency,transmission coefficient,and wave forces on the breakwater of the hybrid system are analyzed.The results indicate that combing the ED WEC with a breakwater can improve the energy extraction performance of the ED WEC and reduce the wave forces on the breakwater in shorter-period waves.The conversion efficiency of the hybrid system with the initial attack angle of 42°is the largest in shorter-period waves,but is reduced with the increase of initial attack angle in longer-period waves.The wave attenuation performance of the hybrid system is determined by the draft of the breakwater.The distance between the WEC and the breakwater has little effect on the hybrid system.Wave energy extraction of the ED WEC of the hybrid system decreases significantly with the increase of the incident wave height.展开更多
With the continuous increase of mining in depth,the gas extraction faces the challenges of low permeability,great ground stress,high temperature and large gas pressure in coal seam.The controllable shock wave(CSW),as ...With the continuous increase of mining in depth,the gas extraction faces the challenges of low permeability,great ground stress,high temperature and large gas pressure in coal seam.The controllable shock wave(CSW),as a new method for enhancing permeability of coal seam to improve gas extraction,features in the advantages of high efficiency,eco-friendly,and low cost.In order to better utilize the CSW into gas extraction in coal mine,the mechanism and feasibility of CSW enhanced extraction need to be studied.In this paper,the basic principles,the experimental tests,the mathematical models,and the on-site tests of CSW fracturing coal seams are reviewed,thereby its future research directions are provided.Based on the different media between electrodes,the CSW can be divided into three categories:hydraulic effect,wire explosion and excitation of energetic materials by detonating wire.During the process of propagation and attenuation of the high-energy shock wave in coal,the shock wave and bubble pulsation work together to produce an enhanced permeability effect on the coal seam.The stronger the strength of the CSW is,the more cracks created in the coal is,and the greater the length,width and area of the cracks being.The repeated shock on the coal seam is conducive to the formation of complex network fracture system as well as the reduction of coal seam strength,but excessive shock frequency will also damage the coal structure,resulting in the limited effect of the enhanced gas extraction.Under the influence of ground stress,the crack propagation in coal seam will be restrained.The difference of horizontal principal stress has a significant impact on the shape,propagation direction and connectivity of the CSW induced cracks.The permeability enhancement effect of CSW is affected by the breakage degree of coal seam.The shock wave is absorbed by the broken coal,which may hinder the propagation of CSW,resulting in a poor effect of permeability enhancement.When arranging two adjacent boreholes for CSW permeability enhancement test,the spacing of boreholes should not be too close,which may lead to negative pressure mutual pulling in the early stage of drainage.At present,the accurate method for effectively predicting the CSW permeability enhanced range should be further investigated.展开更多
[Objectives]The extraction conditions of formula oolong tea were investigated by an orthogonal experiment.[Methods]The technical conditions were optimized by the 4C method,and the application of formula oolong tea ext...[Objectives]The extraction conditions of formula oolong tea were investigated by an orthogonal experiment.[Methods]The technical conditions were optimized by the 4C method,and the application of formula oolong tea extract in cigarettes was studied.[Results]①In the experimental range,the best sensory evaluation effect of formula oolong tea extract was obtained with extraction conditions of 70%ethanol as extraction solvent,extraction time h,extraction temperature 25℃,and ultrasonic frequency 80 kHz,and follow-up low-temperature concentration,low-temperature sedimentation and low-temperature centrifugation.②The effects of different centrifugal speeds on the quality of formula oolong tea extract were explored.The formula oolong tea extract obtained under the conditions of 3000 r/min and centrifugal time of 10 min showed the best evaluation effect with soft and delicate smoke,rich smoke fragrance,good comfort and refreshing mouthfeel.③The effective aroma components in the formula oolong tea extract were qualitatively analyzed by GC-MS.[Conclusions]This study provides high-quality raw materials and a theoretical basis for the research of independent flavor blending in cigarette industry enterprises.展开更多
Copper-bearing biotite is a refractory copper mineral found on the surface of the Zambian Copperbelt.Biotite is a copper oxide from which copper is extracted by various methods,especially by leaching.Leaching is the p...Copper-bearing biotite is a refractory copper mineral found on the surface of the Zambian Copperbelt.Biotite is a copper oxide from which copper is extracted by various methods,especially by leaching.Leaching is the process of extracting a substance from a solid material dissolved in a liquid.To improve the efficiency of the leaching process by a more effective method,a new method called ultrasonic-assisted acid leaching is proposed and applied in this study.Compared with regular acid leaching,the ultrasound method reduced the leaching time from 120 to 40 min,and sulfuric acid concentration reduced from 0.5 to 0.3 mol·L^(-1).Besides,leaching temperature could be reduced from 75 to 45°C at the leaching rate of 78%.The mechanism analysis indicates that an ultrasonic wave can cause the delamination of a copper-bearing biotite and increase its specific surface area from 0.55 to 1.67 m^(2)·g^(-1).The results indicate that copper extraction from copper-bearing biotite by ultrasonic-assisted acid leaching is more effective than regular acid leaching.This study proposes a promising method for recycling valuable metals from phyllosilicate minerals.展开更多
The problem of measuring exterior ballistic feature points is always difficult to solve and it is essentiale on exterior ballistic measurement.By analysis of radar reflection characteristics and non-stationary echo si...The problem of measuring exterior ballistic feature points is always difficult to solve and it is essentiale on exterior ballistic measurement.By analysis of radar reflection characteristics and non-stationary echo signals of exterior ballistic feature points,the echo data of exterior ballistic feature points is measured by using the continuous wave radar.The parameters of feature points are extracted by the empirical mode decomposition method(EMD)of Hilbert-Huang transform(HHT)spectrum analysis technique.The radar echo signal model and EMD extraction model are established to analyze the exterior ballistic mutation point detection and EMD extraction method of aliasing echo signal.Typical feature point parameters of exterior ballistic in rocket flight tests are carried out and the effectiveness of the method is verified.A new method of measuring the parameters of exterior ballistic feature point is therefore presented.展开更多
A multi-chamber oscillating water column wave energy converter(OWC-WEC)integrated to a breakwater is investigated.The hydrodynamic characteristics of the device are analyzed using an analytical model based on the line...A multi-chamber oscillating water column wave energy converter(OWC-WEC)integrated to a breakwater is investigated.The hydrodynamic characteristics of the device are analyzed using an analytical model based on the linear potential flow theory.A pneumatic model is employed to investigate the relationship between the air mass flux in the chamber and the turbine characteristics.The effects of chamber width,wall draft and wall thickness on the hydrodynamic performance of a dual-chamber OWC-WEC are investigated.The results demonstrate that the device,with a smaller front wall draft and a wider rear chamber exhibits a broader effective frequency bandwidth.The device with a chamber-width-ratio of 1:3 performs better in terms of power absorption.Additionally,results from the analysis of a triplechamber OWC-WEC demonstrate that reducing the front chamber width and increasing the rearward chamber width can improve the total performance of the device.Increasing the number of chambers from 1 to 2 or 3 can widen the effective frequency bandwidth.展开更多
It takes flavonoid extraction rate as indicator and adopts the method of orthogonal experiment to study process of total flavonoid in Trollius chinensis through ultrasonic wave assisted extraction, microwave assisted ...It takes flavonoid extraction rate as indicator and adopts the method of orthogonal experiment to study process of total flavonoid in Trollius chinensis through ultrasonic wave assisted extraction, microwave assisted extraction and backflow extraction, as well as optimization of process parameter. The result indicates that in terms of extraction efficiency, microwave extraction method is better than ultrasonic radiation extraction method, which is better than backflow extraction method. Optimal process parameter through backflow extraction is： backflow temperature 60℃, fluid material ratio 1：20, ethanol density 65%, backflow time 60min; optimal process parameter through ultrasonic wave assisted extraction is： ultrasonic radiation temperature 70℃, fluid material ratio 1：20, ethanol density 65%, ultrasonic wave radiation time 45rain; optimal process parameter of microwave assisted extraction is： microwave radiation temperature 60℃, fluid material ratio 1：20, ethanol density 75%, microwave radiation time 45min.展开更多
With technology advances and human requirements increasing, human-computer interaction plays an important role in our daily lives. Among these interactions, gesture-based recognition offers a natural and intuitive use...With technology advances and human requirements increasing, human-computer interaction plays an important role in our daily lives. Among these interactions, gesture-based recognition offers a natural and intuitive user experience that does not require physical contact and is becoming increasingly prevalent across various fields. Gesture recognition systems based on Frequency Modulated Continuous Wave (FMCW) millimeter-wave radar are receiving widespread attention due to their ability to operate without wearable sensors, their robustness to environmental factors, and the excellent penetrative ability of radar signals. This paper first reviews the current main gesture recognition applications. Subsequently, we introduce the system of gesture recognition based on FMCW radar and provide a general framework for gesture recognition, including gesture data acquisition, data preprocessing, and classification methods. We then discuss typical applications of gesture recognition systems and summarize the performance of these systems in terms of experimental environment, signal acquisition, signal processing, and classification methods. Specifically, we focus our study on four typical gesture recognition systems, including air-writing recognition, gesture command recognition, sign language recognition, and text input recognition. Finally, this paper addresses the challenges and unresolved problems in FMCW radar-based gesture recognition and provides insights into potential future research directions.展开更多
海岸带是陆地、海洋、大气相互作用的地球生态关键带,汇集了大量的物质和能量,正经历着高强度人类活动、全球气候变化和物种入侵的叠加影响,面临着前所未有的挑战。遥感科学与技术是全面、系统、深入监测海岸带资源、生态、环境的有效...海岸带是陆地、海洋、大气相互作用的地球生态关键带,汇集了大量的物质和能量,正经历着高强度人类活动、全球气候变化和物种入侵的叠加影响,面临着前所未有的挑战。遥感科学与技术是全面、系统、深入监测海岸带资源、生态、环境的有效手段。本文从海岸带独特性和遥感技术优势出发,借助Web of Science和CNKI数据库,分析了海岸带遥感国内外研究现状,探讨了海岸带遥感所面临的科学技术问题,综述了研究进展,明确了机遇与挑战,讨论了未来发展方向。本文可为科学认识海岸带遥感中存在的问题,把握海岸带遥感发展方向提供参考。展开更多
ICESat-2(Ice,Cloud and Land Elevation Satellite 2)卫星激光雷达数据被广泛应用于地形地貌测绘、森林监测、水域监测等多个领域。当ICESat-2飞越海面时,可以检测到被海面反射回的微弱光子信号,其反映了海面的起伏状态,但同时也包含...ICESat-2(Ice,Cloud and Land Elevation Satellite 2)卫星激光雷达数据被广泛应用于地形地貌测绘、森林监测、水域监测等多个领域。当ICESat-2飞越海面时,可以检测到被海面反射回的微弱光子信号,其反映了海面的起伏状态,但同时也包含了设备噪声、大气颗粒散射噪声、背景干扰噪声等大量噪声光子。本研究提出了一种新的海面信号光子提取和海浪要素反演方法,首先将原始ICESat-2数据沿垂直方向均匀分段,统计各段内光子数,对其进行高斯拟合和迭代中值滤波,确定精确的海面光子上下界,从而提取出海面信号光子。进一步采用支持向量回归拟合,提取瞬时海面轮廓。在此基础上,利用频谱分析方法计算出有效波高和初步海浪峰值波长,通过对同步的强弱激光束相位相干分析,估算海浪波向,并修正海浪峰值波长和计算海浪峰值周期。对来自好望角和萨摩亚海域的24条轨道ICESat-2数据进行海面光子提取和海浪要素反演,并将结果与ERA5再分析数据进行对比验证。结果表明,海浪有效波高、波向和峰值周期的均方根误差(RMSE)分别为0.12 m、28.58°和0.48 s,表明该方法具有较高的海浪要素反演精度,具备进一步探索更大范围激光雷达数据海浪要素提取和分析的潜力。展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.52071096)the Student Research and Innovation Fund of the Fundamental Research Funds for the Central Universities(Grant No.3072020GIP0105).
文摘Edinburgh Duck wave energy converter(ED WEC)has excellent energy extraction performance and shows a great potential to integrate with other marine structures.This paper aims to investigate its wave energy extraction performance as a WEC and wave attenuation performance as a protection method for shoreline or marine structures.The wave and ED WEC interactions in regular waves are modeled using the Star-CCM+software and verified by comparisons with published experimental results.The motion response,energy conversion efficiency,and transmission coefficient of the ED WEC with different attack angles,rotation center,and incident wave heights are investigated.Results indicate that the ED WEC with an attack angle of 42°and a rotation center of 0.55 m below the mean water line can achieve both good wave energy extraction and wave attenuation performances.The wave energy extraction and wave attenuation performance of the ED WEC decrease significantly with the increase of wave nonlinearity characterized by the wave steepness.This paper can guide the practical application of the ED WEC at the early stage of design.
基金financially supported by the National Natural Science Foundation of China (Grant No. 52071096)the Student Research and Innovation Fund of the Fundamental Research Funds for the Central Universities (Grant No. 3072020GIP0105)。
文摘Installing the Edinburgh Duck Wave Energy Converter(ED WEC)on a floating breakwater provides a potential solution to reduce costs and improve the reliability of the ED WEC.To investigate the interactions between the ED WEC and the breakwater,a two-dimensional numerical model of a hybrid WEC-breakwater system is established based on Star-CCM+Computational Fluid Dynamics(CFD)software.The wave energy extraction performance,wave attenuation performance,and wave forces on the breakwater of the hybrid system are compared with those of the corresponding single device.The effects of the initial attack angle,the distance between the WEC and the breakwater,and the incident wave height on the pitch motion,energy conversion efficiency,transmission coefficient,and wave forces on the breakwater of the hybrid system are analyzed.The results indicate that combing the ED WEC with a breakwater can improve the energy extraction performance of the ED WEC and reduce the wave forces on the breakwater in shorter-period waves.The conversion efficiency of the hybrid system with the initial attack angle of 42°is the largest in shorter-period waves,but is reduced with the increase of initial attack angle in longer-period waves.The wave attenuation performance of the hybrid system is determined by the draft of the breakwater.The distance between the WEC and the breakwater has little effect on the hybrid system.Wave energy extraction of the ED WEC of the hybrid system decreases significantly with the increase of the incident wave height.
基金National Natural Science Foundation of China(52004117,52174117 and 52074146)Postdoctoral Science Foundation of China(2021T140290 and 2020M680975)Basic scientific research project of Liaoning Provincial Department of Education(JYTZD2023073).
文摘With the continuous increase of mining in depth,the gas extraction faces the challenges of low permeability,great ground stress,high temperature and large gas pressure in coal seam.The controllable shock wave(CSW),as a new method for enhancing permeability of coal seam to improve gas extraction,features in the advantages of high efficiency,eco-friendly,and low cost.In order to better utilize the CSW into gas extraction in coal mine,the mechanism and feasibility of CSW enhanced extraction need to be studied.In this paper,the basic principles,the experimental tests,the mathematical models,and the on-site tests of CSW fracturing coal seams are reviewed,thereby its future research directions are provided.Based on the different media between electrodes,the CSW can be divided into three categories:hydraulic effect,wire explosion and excitation of energetic materials by detonating wire.During the process of propagation and attenuation of the high-energy shock wave in coal,the shock wave and bubble pulsation work together to produce an enhanced permeability effect on the coal seam.The stronger the strength of the CSW is,the more cracks created in the coal is,and the greater the length,width and area of the cracks being.The repeated shock on the coal seam is conducive to the formation of complex network fracture system as well as the reduction of coal seam strength,but excessive shock frequency will also damage the coal structure,resulting in the limited effect of the enhanced gas extraction.Under the influence of ground stress,the crack propagation in coal seam will be restrained.The difference of horizontal principal stress has a significant impact on the shape,propagation direction and connectivity of the CSW induced cracks.The permeability enhancement effect of CSW is affected by the breakage degree of coal seam.The shock wave is absorbed by the broken coal,which may hinder the propagation of CSW,resulting in a poor effect of permeability enhancement.When arranging two adjacent boreholes for CSW permeability enhancement test,the spacing of boreholes should not be too close,which may lead to negative pressure mutual pulling in the early stage of drainage.At present,the accurate method for effectively predicting the CSW permeability enhanced range should be further investigated.
文摘[Objectives]The extraction conditions of formula oolong tea were investigated by an orthogonal experiment.[Methods]The technical conditions were optimized by the 4C method,and the application of formula oolong tea extract in cigarettes was studied.[Results]①In the experimental range,the best sensory evaluation effect of formula oolong tea extract was obtained with extraction conditions of 70%ethanol as extraction solvent,extraction time h,extraction temperature 25℃,and ultrasonic frequency 80 kHz,and follow-up low-temperature concentration,low-temperature sedimentation and low-temperature centrifugation.②The effects of different centrifugal speeds on the quality of formula oolong tea extract were explored.The formula oolong tea extract obtained under the conditions of 3000 r/min and centrifugal time of 10 min showed the best evaluation effect with soft and delicate smoke,rich smoke fragrance,good comfort and refreshing mouthfeel.③The effective aroma components in the formula oolong tea extract were qualitatively analyzed by GC-MS.[Conclusions]This study provides high-quality raw materials and a theoretical basis for the research of independent flavor blending in cigarette industry enterprises.
基金financially supported by the National Natural Science Foundation of China(No.51574018)。
文摘Copper-bearing biotite is a refractory copper mineral found on the surface of the Zambian Copperbelt.Biotite is a copper oxide from which copper is extracted by various methods,especially by leaching.Leaching is the process of extracting a substance from a solid material dissolved in a liquid.To improve the efficiency of the leaching process by a more effective method,a new method called ultrasonic-assisted acid leaching is proposed and applied in this study.Compared with regular acid leaching,the ultrasound method reduced the leaching time from 120 to 40 min,and sulfuric acid concentration reduced from 0.5 to 0.3 mol·L^(-1).Besides,leaching temperature could be reduced from 75 to 45°C at the leaching rate of 78%.The mechanism analysis indicates that an ultrasonic wave can cause the delamination of a copper-bearing biotite and increase its specific surface area from 0.55 to 1.67 m^(2)·g^(-1).The results indicate that copper extraction from copper-bearing biotite by ultrasonic-assisted acid leaching is more effective than regular acid leaching.This study proposes a promising method for recycling valuable metals from phyllosilicate minerals.
基金Supported by the National Natural Science Foundation of China(61174219,51677192)
文摘The problem of measuring exterior ballistic feature points is always difficult to solve and it is essentiale on exterior ballistic measurement.By analysis of radar reflection characteristics and non-stationary echo signals of exterior ballistic feature points,the echo data of exterior ballistic feature points is measured by using the continuous wave radar.The parameters of feature points are extracted by the empirical mode decomposition method(EMD)of Hilbert-Huang transform(HHT)spectrum analysis technique.The radar echo signal model and EMD extraction model are established to analyze the exterior ballistic mutation point detection and EMD extraction method of aliasing echo signal.Typical feature point parameters of exterior ballistic in rocket flight tests are carried out and the effectiveness of the method is verified.A new method of measuring the parameters of exterior ballistic feature point is therefore presented.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.U22A20242,52271260,52001054)Natural Science Foundation of Liaoning Province(Grant No.2021-BS-060)Fundamental Research Funds for the Central Universities(Grant No.DUT23RC(3)017)。
文摘A multi-chamber oscillating water column wave energy converter(OWC-WEC)integrated to a breakwater is investigated.The hydrodynamic characteristics of the device are analyzed using an analytical model based on the linear potential flow theory.A pneumatic model is employed to investigate the relationship between the air mass flux in the chamber and the turbine characteristics.The effects of chamber width,wall draft and wall thickness on the hydrodynamic performance of a dual-chamber OWC-WEC are investigated.The results demonstrate that the device,with a smaller front wall draft and a wider rear chamber exhibits a broader effective frequency bandwidth.The device with a chamber-width-ratio of 1:3 performs better in terms of power absorption.Additionally,results from the analysis of a triplechamber OWC-WEC demonstrate that reducing the front chamber width and increasing the rearward chamber width can improve the total performance of the device.Increasing the number of chambers from 1 to 2 or 3 can widen the effective frequency bandwidth.
文摘It takes flavonoid extraction rate as indicator and adopts the method of orthogonal experiment to study process of total flavonoid in Trollius chinensis through ultrasonic wave assisted extraction, microwave assisted extraction and backflow extraction, as well as optimization of process parameter. The result indicates that in terms of extraction efficiency, microwave extraction method is better than ultrasonic radiation extraction method, which is better than backflow extraction method. Optimal process parameter through backflow extraction is： backflow temperature 60℃, fluid material ratio 1：20, ethanol density 65%, backflow time 60min; optimal process parameter through ultrasonic wave assisted extraction is： ultrasonic radiation temperature 70℃, fluid material ratio 1：20, ethanol density 65%, ultrasonic wave radiation time 45rain; optimal process parameter of microwave assisted extraction is： microwave radiation temperature 60℃, fluid material ratio 1：20, ethanol density 75%, microwave radiation time 45min.
文摘With technology advances and human requirements increasing, human-computer interaction plays an important role in our daily lives. Among these interactions, gesture-based recognition offers a natural and intuitive user experience that does not require physical contact and is becoming increasingly prevalent across various fields. Gesture recognition systems based on Frequency Modulated Continuous Wave (FMCW) millimeter-wave radar are receiving widespread attention due to their ability to operate without wearable sensors, their robustness to environmental factors, and the excellent penetrative ability of radar signals. This paper first reviews the current main gesture recognition applications. Subsequently, we introduce the system of gesture recognition based on FMCW radar and provide a general framework for gesture recognition, including gesture data acquisition, data preprocessing, and classification methods. We then discuss typical applications of gesture recognition systems and summarize the performance of these systems in terms of experimental environment, signal acquisition, signal processing, and classification methods. Specifically, we focus our study on four typical gesture recognition systems, including air-writing recognition, gesture command recognition, sign language recognition, and text input recognition. Finally, this paper addresses the challenges and unresolved problems in FMCW radar-based gesture recognition and provides insights into potential future research directions.
文摘海岸带是陆地、海洋、大气相互作用的地球生态关键带,汇集了大量的物质和能量,正经历着高强度人类活动、全球气候变化和物种入侵的叠加影响,面临着前所未有的挑战。遥感科学与技术是全面、系统、深入监测海岸带资源、生态、环境的有效手段。本文从海岸带独特性和遥感技术优势出发,借助Web of Science和CNKI数据库,分析了海岸带遥感国内外研究现状,探讨了海岸带遥感所面临的科学技术问题,综述了研究进展,明确了机遇与挑战,讨论了未来发展方向。本文可为科学认识海岸带遥感中存在的问题,把握海岸带遥感发展方向提供参考。
文摘ICESat-2(Ice,Cloud and Land Elevation Satellite 2)卫星激光雷达数据被广泛应用于地形地貌测绘、森林监测、水域监测等多个领域。当ICESat-2飞越海面时,可以检测到被海面反射回的微弱光子信号,其反映了海面的起伏状态,但同时也包含了设备噪声、大气颗粒散射噪声、背景干扰噪声等大量噪声光子。本研究提出了一种新的海面信号光子提取和海浪要素反演方法,首先将原始ICESat-2数据沿垂直方向均匀分段,统计各段内光子数,对其进行高斯拟合和迭代中值滤波,确定精确的海面光子上下界,从而提取出海面信号光子。进一步采用支持向量回归拟合,提取瞬时海面轮廓。在此基础上,利用频谱分析方法计算出有效波高和初步海浪峰值波长,通过对同步的强弱激光束相位相干分析,估算海浪波向,并修正海浪峰值波长和计算海浪峰值周期。对来自好望角和萨摩亚海域的24条轨道ICESat-2数据进行海面光子提取和海浪要素反演,并将结果与ERA5再分析数据进行对比验证。结果表明,海浪有效波高、波向和峰值周期的均方根误差(RMSE)分别为0.12 m、28.58°和0.48 s,表明该方法具有较高的海浪要素反演精度,具备进一步探索更大范围激光雷达数据海浪要素提取和分析的潜力。
