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Data Quality Control Method of a New Drifting Observation Technology Named Drifting Air-Sea Interface Buoy 被引量:1
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作者 LI Shuo WANG Bin +3 位作者 DENG Zeng’an WU Baoqin ZHU Xiande CHEN Zhaohui 《Journal of Ocean University of China》 CAS CSCD 2024年第1期11-22,共12页
An integral quality control(QC)procedure that integrates various QC methods and considers the design indexes and operational status of the instruments for the observations of drifting air-sea interface buoy was develo... An integral quality control(QC)procedure that integrates various QC methods and considers the design indexes and operational status of the instruments for the observations of drifting air-sea interface buoy was developed in the order of basic in-spection followed by targeted QC.The innovative method of combining a moving Hampel filter and local anomaly detection com-plies with statistical laws and physical processes,which guarantees the QC performance of meteorological variables.Two sets of observation data were used to verify the applicability and effectiveness of the QC procedure,and the effect was evaluated using the observations of the Kuroshio Extension Observatory buoy as the reference.The results showed that the outliers in the time series can be correctly identified and processed,and the quality of data improved significantly.The linear correlation between the quality-controlled observations and the reference increased,and the difference decreased.The correlation coefficient of wind speed before and after QC increased from 0.77 to 0.82,and the maximum absolute error decreased by approximately 2.8ms^(-1).In addition,air pressure and relative humidity were optimized by 10^(-3)–10^(-2) orders of magnitude.For the sea surface temperature,the weight of coefficients of the continuity test algorithm was optimized based on the sea area of data acquisition,which effectively expanded the applicability of the algorithm. 展开更多
关键词 drifting air-sea interface buoy quality control oceanic variables meteorological variables continuity test
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Field Testing Methodology for Wave Energy Converters Using the MIKE 21 Model 被引量:1
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作者 Ning Jia Xiangnan Wang +1 位作者 Linsheng Han Hainan Xia 《Energy Engineering》 2025年第6期2389-2400,共12页
With the depletion of fossil fuels and increasing environmental concerns,the development of renewable energy,such as wave energy,has become a critical component of global energy strategies.However,challenges persist i... With the depletion of fossil fuels and increasing environmental concerns,the development of renewable energy,such as wave energy,has become a critical component of global energy strategies.However,challenges persist in the field testing methodologies for wave energy converters(WECs).In this paper,a numerical wave field of the Dawanshan Island Sea Area in Zhuhai City is constructed based on the MIKE21 SW wave model and by using an NCEP wind field driving model.In conjunction with the IEC-62600-100 standard,by taking site testing of the“Wanshan”wave energy converter on which a sea trial has been conducted in Dawanshan Island of Zhuhai city as an example,research on-site testing method for a wave energy converter has been carried out.The wave measurement position for the“Wanshan”converter was determined by combining statistically analyzed field data with a validated numerical wave model.By comparing a valid wave height at the position where a wave rider is located with a valid wave height at the position where the“Wanshan”wave energy converter is situated,the correlation coefficient between simulation and observed data reached 0.90,with a root-mean-square error of 0.19.The representativeness of wave measurement data during site testing is verified and can be used as a basis for calculating the input energy of the“Wanshan”wave energy converter. 展开更多
关键词 Wave energy converter site testing MIKE21 SW model
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Design of an OFDM Algorithm for Improving the Transmission Performance of a Deep-Sea Long-Distance Electric Current Channel
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作者 ZHENG Yu PENG Bo +2 位作者 SONG Rujuan LIU Yingjie LI Hongzhi 《Journal of Ocean University of China》 2025年第3期647-656,共10页
This study investigates inductively coupled transmission technology using seawater and underwater anchor chains as the transmission medium for real-time data transfer from underwater measurement instruments.Because of... This study investigates inductively coupled transmission technology using seawater and underwater anchor chains as the transmission medium for real-time data transfer from underwater measurement instruments.Because of the physical properties of seawater,challenges,such as frequency selective fading and multipath effect,limit long-distance current signal transmission.Conventional modulation techniques,such as amplitude shift keying(ASK)and differential phase shift keying(DPSK),are constrained by low bandwidth utilization and high bit error rates(BER).To address these issues,we optimize the seawater channel model using data from the National Oceanographic Data Center and previous measurements,analyzing the relationship between seawater conductivity,depth,and signal frequency.We constructed an experimental platform using a six-winding manganese-zinc ferrite ring based on an inductive coupling model for data transmission.A steel cable is anchored at both ends of a seawater bucket through two rings,exposing the cable core to establish a closed loop in seawater.An orthogonal frequency division multiplexing(OFDM)algorithm is used to improve transmission performance by distributing data across multiple subcarriers,effectively mitigating multipath fading and frequency selective fading.Compared with ASK and DPSK,this method significantly reduces the BER and improves the channel capacity,exhibiting robustness in underwater communication.Finally,in our study,a mathematical model of the underwater multipath channel for distances of 300,1000,and 2000 m is established,showing an improvement in channel capacity of approximately 2.5 bps/Hz based on the OFDM algorithm.This advancement is essential for enhancing the performance of underwater signal transmission and supporting its practical application. 展开更多
关键词 deep sea inductively coupled transmission technology long-distance underwater current channel OFDM transmission performance
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Improving the Antifouling Properties of CTD During the Marine Field Tests:The Use of CAP@MMT Modified with Acid
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作者 CHE Yachen WEI Lianxue +2 位作者 DIAO Yaqi JIA Wenjuan LI Hongzhi 《Journal of Ocean University of China》 2025年第3期685-694,共10页
The use of antifouling agents is suggested to be a promising method for protecting oceanic instruments from biological contamination.We developed a novel antifouling material doped with capsaicin(CAP)as a filler and m... The use of antifouling agents is suggested to be a promising method for protecting oceanic instruments from biological contamination.We developed a novel antifouling material doped with capsaicin(CAP)as a filler and montmorillonite(MMT)as a carrier for the practical application of CTD(conductivity,temperature,depth)protection.The optimal parameters for preparing the material were established,and the obtained material achieved the maximum CAP loading capacity of 32.74%.The proposed material exhibited great release properties in acidic environments,which is beneficial for reducing bacterial attachment.Furthermore,the optimal conditions(temperature,flow rate,and pressure in the aquatic environment)for a better release rate of the material were determined through a series of simulation tests in lab.It provided good guidance and basis for practical application of the material.The CAP@MMT composite showed excellent efficiency and effectiveness in preventing the attachment of microorganisms during the four-month marine field tests.In the subsequent experiments,the great properties of the antifouling material were further confirmed by retesting the conductivity of four instruments participating in marine field tests.The measuring errors of CTD protected by the antifouling material are both within 0.01 mS/cm,which is far lower than that of the other two instruments. 展开更多
关键词 marine fouling antifouling agent CAP@MMT PH-DEPENDENT marine field tests
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Extraction of Modal Depth Functions and Wavenumbers Using Full Rank Decomposition Method with a Vertical Line Array
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作者 ZHANG Shuang ZHANG Yinquan +3 位作者 QIN Jinxing LI Zhenglin GUO Yonggang WU Shuanglin 《Journal of Ocean University of China》 2025年第3期672-684,共13页
Normal mode extraction has attracted extensive attention over the past few decades due to its practical value in enhancing the performance of underwater acoustic signal processing.Singular value decomposition(SVD)is a... Normal mode extraction has attracted extensive attention over the past few decades due to its practical value in enhancing the performance of underwater acoustic signal processing.Singular value decomposition(SVD)is an effective method to extract modal depth functions using vertical line arrays(VLA),particularly in scenarios when no prior environment information is available.However,the SVD method requires rigorous orthogonality conditions,and its performance severely degenerates in the presence of mode degeneracy.Consequently,the SVD approach is often not feasible in practical scenarios.This paper proposes a full rank decomposition(FRD)method to address these issues.Compared to the SVD method,the FRD method has three distinct advantages:1)the conditions that the FRD method requires are much easier to be fulfilled in practical scenarios;2)both modal depth functions and wavenumbers can be simultaneously extracted via the FRD method;3)the FRD method is not affected by the phenomenon of mode degeneracy.Numerical simulations are conducted in two types of waveguides to verify the FRD method.The impacts of environment configurations and noise levels on the precision of the extracted modal depth functions and wavenumbers are also investigated through simulation. 展开更多
关键词 normal mode extraction modal depth function modal wavenumber full rank decomposition
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Multi-Hazard Assessment of Storm Surge Events Using the System Energy Equivalence Model
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作者 XIE Xiaoru GUO Peifang +1 位作者 LI Jing ZHANG Kuncheng 《Journal of Ocean University of China》 2025年第3期569-582,共14页
Storm surge events(SSEs)involve multiple hazard-causing factors,such as surges,extreme rainfall,strong winds,waves,and ocean currents,which have destructive impacts on coastal regions.For a quantitative multi-hazard a... Storm surge events(SSEs)involve multiple hazard-causing factors,such as surges,extreme rainfall,strong winds,waves,and ocean currents,which have destructive impacts on coastal regions.For a quantitative multi-hazard assessment of SSEs,this study introduced the concept of the storm surge event seawater-atmosphere system(SSE-SAS)and proposed the system energy equivalence(SEE)model from a systemic energy perspective.SEE was obtained by employing a parameterization approach,and the hazard index(HI)and the concept of most significant hazard(MSH)were adopted to evaluate the severity of SSE-SAS.SEE at five stations in the Shandong Peninsula was calculated from 2005 to 2019,and probability analysis and hazard assessment were further conducted.Results show that the SEE of SSE-SAS ranges from 0.029×10^(3) to 30.418×10^(3) J/m^(2),and it exhibits an insignificant decreasing trend from 2005 to 2019.The SEE of SSE-SAS in the west of the Shandong Peninsula is greater than that in the east.Moreover,storm waves,storm surges,and storm rainfall are the major contributors to SEE,which exhibit different spatial patterns and characters in different SSE-SAS types.The HI of SSE-SAS at five stations is no more than medium hazard level,with MSH at return periods of 2-to 4-year level.This study provides a new approach for quantifying multi-hazard SSEs,which offers scientific insights for regional multi-hazard risk reduction and mitigation efforts. 展开更多
关键词 storm surge multi-hazard system energy equivalence multi-hazard assessment
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Comparative analysis of significant wave height between a new Southern Ocean buoy and satellite altimeter 被引量:3
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作者 Jianjun Kang Runyu Mao +1 位作者 Yiting Chang Hongli Fu 《Atmospheric and Oceanic Science Letters》 CSCD 2021年第5期49-55,共7页
In-situ observation is restricted by the strong wind and waves in the Southern Ocean.A Westerlies EnvironmentalMonitoring Buoy(WEMB)was firstly deployed in the Southern Ocean during China’s 35th Antarctic Expedition,... In-situ observation is restricted by the strong wind and waves in the Southern Ocean.A Westerlies EnvironmentalMonitoring Buoy(WEMB)was firstly deployed in the Southern Ocean during China’s 35th Antarctic Expedition,facilitating further understanding of the oceanic environmental characteristics of this region.With the develop-ment of technology and the improvement of data processing methods,the accuracy of satellite altimeter productsis constantly improved,thus making it possible to inspect and evaluate the in-situ observation data.Based on theL3 products of multiple satellite altimeters,this paper analyzes and corrects the significant wave height(SWH)data of WEMB by means of data matching,error statistics,and linear least-squares fitting.Through this study,the authors obtained the following results.The effect of gravitational acceleration changes with latitude on SWHaccuracy is fairly small.Due to the low response of WEMB to high-frequency waves,there is a systematic devia-tion.A feasible correction method is therefore proposed to improve the SWH accuracy of WEMB.The temporalvariation of the corrected SWH is highly consistent with that of the 10 m wind during the observation period,and its average value reaches 3.8 m. 展开更多
关键词 Mooring buoy Southern ocean Satellite altimeter Significant wave height
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Observed and modelled snow and ice thickness in the Arctic Ocean with CHINARE buoy data 被引量:4
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作者 TIAN Zhongxiang CHENG Bin +4 位作者 ZHAO liechen VIHMA Timo ZHANG Wenliang LI Zhijun ZHANG Zhanhai 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第8期66-75,共10页
Sea ice and the snow pack on top of it were investigated using Chinese National Arctic Research Expedition (CHINARE) buoy data. Two polar hydrometeorological drifters, known as Zeno ice stations, were deployed durin... Sea ice and the snow pack on top of it were investigated using Chinese National Arctic Research Expedition (CHINARE) buoy data. Two polar hydrometeorological drifters, known as Zeno ice stations, were deployed during CHINARE 2003. A new type of high-resolution Snow and Ice Mass Balance Arrays, known as SIMBA buoys, were deployed during CHINARE 2014. Data from those buoys were applied to investigate the thickness of sea ice and snow in the CHINARE domain. A simple approach was applied to estimate the average snow thickness on the basis of Zeno temperature data. Snow and ice thicknesses were also derived from vertical temperature profile data based on the SIMBA buoys. A one-dimensional snow and ice thermodynamic model (HIGHTSI) was applied to calculate the snow and ice thickness along the buoy drift trajectories. The model forcing was based on forecasts and analyses of the European Centre for Medium-Range Weather Forecasts (ECMWF). The Zeno buoys drifted in a confined area during 2003-2004. The snow thickness modelled applying HIGHTSI was consistent with results based on Zeno buoy data. The SIMBA buoys drifted from 81. 1°N, 157.4°W to 73.5°N, 134.9°W in 15 months during 2014-2015. The total ice thickness increased from an initial August 2014 value of 1.97 m to a maximum value of 2.45 in before the onset of snow melt in May 2015; the last observation was approximately 1 m in late November 2015. The ice thickness based on HIGHTSI agreed with SIMBA measurements, in particular when the seasonal variation of oceanic heat flux was taken into account, but the modelled snow thickness differed from the observed one. Sea ice thickness derived from SIMBA data was reasonably good in cold conditions, but challenges remain in both snow and ice thickness in summer. 展开更多
关键词 TEMPERATURE SNOW sea ice thickness ice mass balance buoy Arctic Ocean
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A numerical estimation of the impact of Stokes drift on upper ocean temperature 被引量:3
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作者 ZHANG Xiaoshuang WANG Zhifeng +3 位作者 WANG Bin WU Kejian HAN Guijun LI Wei 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第7期48-55,共8页
The impact of Stokes drift on the mixed layer temperature variation was estimated by taking into account an advective heat transport term induced by the Stokes drift in the equation of mixed layer temperature and usin... The impact of Stokes drift on the mixed layer temperature variation was estimated by taking into account an advective heat transport term induced by the Stokes drift in the equation of mixed layer temperature and using the oceanic and wave parameters from a global ocean circulation model (HYCOM) and a wave model (Wave Watch III). The dimensional analysis and quantitative estimation method were conducted to assess the importance of the effect induced by the Stokes drift and to analyze its spatial distribution and seasonal variation characteristics. Results show that the contribution of the Stokes drift to the mixed layer temperature variation at mid-to-high latitudes is comparable with that of the mean current, and a substantial part of mixed layer temperature change is induced by taking the Stokes drift effect into account. Although the advection heat transport induced by the Stokes drift is not the leading term for the mixed layer temperature equation, it cannot be neglected and even becomes critical in some regions for the simulation of the upperocean temperature. 展开更多
关键词 sea surface waves Stokes drift mixed layer temperature
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Attitude Coordination of Multi-HUG Formation Based on Multibody System Theory 被引量:1
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作者 XUE Dong-yang WU Zhi-liang +2 位作者 QI Er-mai WANG Yan-hui WANG Shu-xin 《China Ocean Engineering》 SCIE EI CSCD 2017年第2期248-255,共8页
Application of multiple hybrid underwater gliders (HUGs) is a promising method for large scale, long-term ocean survey. Attitude coordination has become a requisite for task execution of multi-HUG formation. In this... Application of multiple hybrid underwater gliders (HUGs) is a promising method for large scale, long-term ocean survey. Attitude coordination has become a requisite for task execution of multi-HUG formation. In this paper, a multibody model is presented for attitude coordination among agents in the HUG formation. The HUG formation is regarded as a multi-rigid body system. The interaction between agents in the formation is described by artificial potential field (APF) approach. Attitude control torque is composed of a conservative torque generated by orientation potential field and a dissipative term related with angular velocity. Dynamic modeling of the multibody system is presented to analyze the dynamic process of the HUG formation. Numerical calculation is carried out to simulate attitude synchronization with two kinds of formation topologies. Results show that attitude synchronization can be fulfilled based on the multibody method described in this paper. It is also indicated that different topologies affect attitude control quality with respect to energy consumption and adjusting time. Low level topology should be adopted during formation control scheme design to achieve a better control effect. 展开更多
关键词 hybrid underwater gliders (HUGs) FORMATION attitude coordination multibody system Kane's equation
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Design Method of an Ocean Induction Coupling Chain Communication System that Resists the Multipath Effect of a Seawater Channel
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作者 ZHENG Yu LU Yanfang +1 位作者 FEI Chen LI Hongzhi 《Journal of Ocean University of China》 SCIE CAS CSCD 2021年第1期87-93,共7页
In this study,a mathematical model of multipath channels is established,and the delay parameters of 10-path models are calculated at 300 m.A multipath-channel hardware simulator based on a field programmable gate arra... In this study,a mathematical model of multipath channels is established,and the delay parameters of 10-path models are calculated at 300 m.A multipath-channel hardware simulator based on a field programmable gate array(FPGA)is designed and verified at 100 k Hz,200 k Hz,500 k Hz,1 MHz,and 24 MHz transmission frequencies.According to the characteristics of the ocean induction coupling chain channel,the orthogonal frequency-division multiplexing(OFDM)algorithm parameters are designed by referring to the wireless communication protocol.The appropriate length cyclic prefix(CP)is added in the OFDM symbol to resist the multipath effect of the seawater channel,and the FPGA hardware transceiver based on the OFDM algorithm is realized.The hardware platform of the ocean induction coupling chain communication system is developed to resist the multipath effect of the seawater channel and tested at 24 MHz.The experimental results show that 800 ns is the best CP length for the developed system,which can effectively resist the multipath effect,with a signal-to-noise ratio above 24 d B and a bit error rate below 1%.This study provides a hardware simulation test platform and an effective method to resist the multipath effect of a seawater channel and improve the transmission performance of the seawater channel. 展开更多
关键词 ocean induction coupling chain communication system multipath-channel hardware simulator OFDM FPGA hardware platform
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Orthogonal Frequency Division Multiplexing Adaptive Technology for Multinode Users of Seawater Channel Based on Inductively Coupled Mooring Chain
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作者 ZHENG Yu LIU Yingjie +3 位作者 REN Yuanhong FEI Chen ZHANG Shijiang LI Hongzhi 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第5期1243-1252,共10页
As an important part of buoy-type ocean monitoring systems,the inductively coupled mooring chain solves the problem of data cotransmission through the multinode sensors that it carries,which is significant for the rap... As an important part of buoy-type ocean monitoring systems,the inductively coupled mooring chain solves the problem of data cotransmission through the multinode sensors that it carries,which is significant for the rapid acquisition of fish,hydrology,and other information.This paper is based on a seawater channel transmission model with a depth of 300 m and a bandwidth of 2 MHz.An orthogonal frequency division multiplexing(OFDM)technology is used to overcome the multipath effect of signal transmission on a seawater medium.The adaptive technology is integrated into the OFDM,and an improved joint subcarrier and bit power allocation algorithm is proposed.This algorithm solves the problem of dynamic subcarrier allocation during the cotransmission of underwater multinode user data in seawater channels.The results show that the algorithm complexity can be reduced by 0.18126×10^(-2)s during one complete OFDM system data transmission by the improved greedy algorithm,and a total of 216 bits are transmitted by the OFDM.The normalized channel capacity can be improved by 0.012 bit s^(-1)Hz^(-1).At the bit error ratio(BER)of 10^(-3),the BER performance can be improved by approximately 6 d B.When the numbers of users are 4 and 8,the improved algorithm increases the channel capacity,and the higher the number of users,the more evident the channel capacity improvement effect is.The results of this paper have an important reference value for enhancing the transmission performance of inductively coupled mooring chain underwater multinode data. 展开更多
关键词 inductively coupled mooring chain seawater channel multinode users OFDM adaptive technology
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Seasonal Distribution of Observed Colored Dissolved Organic Matter(CDOM)in the Eastern Indian Ocean
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作者 CAI Xiaoqing MENG Jie +6 位作者 YUAN Chao LIU Rongjie HOU Erhu BI Dayong LI Yaoru QIAN Chengcheng ZHONG Shan 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第4期886-896,共11页
Colored dissolved organic matter(CDOM)is a crucial constituent that affects the optical absorption properties of seawater.Owing to the relatively limited measured data on the spatial distribution characteristics of CD... Colored dissolved organic matter(CDOM)is a crucial constituent that affects the optical absorption properties of seawater.Owing to the relatively limited measured data on the spatial distribution characteristics of CDOM in the tropical eastern Indian Ocean,this study analyzes the optical absorption characteristics of CDOM in the southeast Indian Ocean using the data collected during four seasons from 2013 to 2017.This work also systematically describes the seasonal horizontal and vertical distribution characteristics of CDOM in this area and conducts a preliminary analysis of the relevant factors affecting CDOM absorption characteristics in this region.Results indicate that the CDOM ag(440)during summer was remarkably lower than that in the coastal waters of Europe and coastal waters of China but slightly higher than that in the western and southeast Pacific.The spatial distribution of surface CDOM shows remarkable seasonal differences,and the spatial distribution characteristics of CDOM in the 5°S,92°E region differ between spring/summer and autumn/winter.The values of ag(400)and ag(440)are weak/strong at a surface/subsurface level of 100 m,with differences found between summer and winter.The correlation of CDOM with temperature,salinity,and chlorophyll-a concentration is relatively low,indicating that CDOM is an independent driving mechanism influenced by phytoplankton degradation,photobleaching,and water mixing. 展开更多
关键词 colored dissolved organic matter tropical eastern Indian Ocean distribution characteristics influencing factors
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Development of Ocean Energy Test Field in China
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作者 Chenhua Ni 《Journal of Shipping and Ocean Engineering》 2015年第1期44-49,共6页
The mission of the test field is to provide technical support to associates. The paper present the development of OE (ocean energy) field in China and outline the new technologies and best practice, resources condit... The mission of the test field is to provide technical support to associates. The paper present the development of OE (ocean energy) field in China and outline the new technologies and best practice, resources conditions, construction targets, generation device testing and standard system. The main purpose is to improve the level of China's ocean energy development. The Chinese ocean energy test field, which was started in 2008, involved a development divided in three phases (the overall design, construction, demonstration). The methodology followed in the individual phases is described, and the standardization of testing wave and tidal current energy devices is introduced. The research revealed the development and the shortage of ocean energy technology in China. 展开更多
关键词 Ocean energy test field device testing standardization.
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Long-Term Extreme Wave Characteristics in the Water Adjacent to China Based on ERA5 Reanalysis Data 被引量:1
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作者 DU Wenyan ZHANG Xuri +4 位作者 SHI Hongyuan LI Guanyu ZHOU Zhengqiao YOU Zaijin ZHANG Kuncheng 《Journal of Ocean University of China》 CAS CSCD 2024年第1期1-10,共10页
Extreme waves have a profound impact on coastal infrastructure;thus,understanding the variation law of risky analysis and disaster prevention in coastal zones is necessary.This paper analyzed the spatiotemporal charac... Extreme waves have a profound impact on coastal infrastructure;thus,understanding the variation law of risky analysis and disaster prevention in coastal zones is necessary.This paper analyzed the spatiotemporal characteristics of extreme wave heights adjacent to China from 1979 to 2018 based on the ERA5 datasets.Nonstationary extreme value analysis is undertaken in eight repre-sentative points to investigate the trends in the values of 50-and 100-year wave heights.Results show that the mean value of extreme waves is the largest in the eastern part of Taiwan Island and the smallest in the Bohai Sea from 1979 to 2018.Only the extreme wave height in the northeastern part of Taiwan Island shows a significant increase trend in the study area.Nonstationary analysis shows remarkable variations in the values of 50-and 100-year significant wave heights in eight points.Considering the annual mean change,E1,E2,S1,and S2 present an increasing trend,while S3 shows a decreasing trend.Most points for the seasonal mean change demon-strate an increasing trend in spring and winter,while other points show a decreasing trend in summer and autumn.Notably,the E1 point growth rate is large in autumn,which is related to the change in typhoon intensity and the northward movement of the typhoon path. 展开更多
关键词 extreme wave height NEVA wave climate ERA5 reanalysis
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Underwater Image Transmission Method and Realization Based on Inductively Coupled Mooring Chain
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作者 ZHENG Yu LIU Yingjie +1 位作者 SONG Rujuan LI Hongzhi 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第6期1503-1514,共12页
Inductively coupled mooring chain transmission technology plays a crucial role in the long-distance online monitoring of marine hydrographic information.However,the impedance characteristics of the seawater medium pos... Inductively coupled mooring chain transmission technology plays a crucial role in the long-distance online monitoring of marine hydrographic information.However,the impedance characteristics of the seawater medium pose a limitation on its capability to achieve high-speed real-time transmission of underwater images.In this paper,based on the principle of inductively coupled transmission for marine applications,the selected 1920×1080 pixel images are segmented,packaged,and then transmitted to the sending node using the user datagram protocol(UDP),and the modulation and demodulation of the transmitted images are realized using the orthogonal frequency division multiplexing(OFDM)algorithm of least squares(LS)estimation,and eight combinations with different mapping modes and coding rates are tested in the bandwidth of 200-800 k Hz and the quality of the transmitted images is evaluated using three criteria:mean squared error(MSE),peak signal to noise ratio(PSNR),and structural similarity index(SSIM).The results indicate that the image transmission quality is optimal when the mapping method is 16-quadrature amplitude modulation(16QAM),the coding rate is 1/2,and the center frequency is 800 k Hz.Under these conditions,the maximum transmission rate is 0.84 Mbit s^(-1),the SSIM criterion exceeds 0.91690 d B,and the learned perceptual image patch similarity(LPIPS)is less than 0.06000.This paper provides a solution for the underwater image transmission of inductively coupled mooring chains for marine applications. 展开更多
关键词 OCEAN inductively coupled mooring chain underwater image OFDM data communication
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First six months quality assessment of HY-2A SCAT wind products using in situ measurements 被引量:12
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作者 WANG He ZHU Jianhua +5 位作者 LIN Mingsen HUANG Xiaoqi ZHAO Yili CHEN Chuntao ZHANG Youguang PENG Hailong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第11期27-33,共7页
The first Chinese microwave ocean environment satellite HY-2A, carrying a Ku-band scatteromenter (SCAT), was successfully launched in August 2011. The first quality assessment of HY-2A SCAT wind products is presente... The first Chinese microwave ocean environment satellite HY-2A, carrying a Ku-band scatteromenter (SCAT), was successfully launched in August 2011. The first quality assessment of HY-2A SCAT wind products is presented through the comparison of the first 6 months operationally released SCAT products with in situ data. The in situ winds from the National Data Buoy Center (NDBC) buoys, R/V Polarstern, Aurora Australis, Roger Revelle and PY30-1 oil platform, were converted to the 10 m equivalent neutral winds. The temporal and spatial differences between the HY-2A SCAT and the in situ observations were limited to less than 5 min and 12.5 km. For HY-2A SCAT wind speed products, the comparison and analysis using the NDBC buoys yield a bias of-0.49 m/s, a root mean square error (RMSE) of 1.3 m/s and an increase negative bias with increasing wind speed observation above 3 m/s. Although less accurate of HY-2A SCAT wind direction at low winds, the RMSE of 19.19° with a bias of 0.92° is found for wind speeds higher than 3 m/s. These results are found consistent with those from R/Vs and oil platform comparisons. Moreover, the NDBC buoy comparison results also suggest that the accuracy of HY-2A SCAT winds is consistent over the first half year of 2012. The encouraging assessment results over the first 6 months show that wind products from HY-2A SCAT will be useful for scientific community. 展开更多
关键词 HY-2A satellite microwave scatterometer WIND validation
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Absolute calibration of HY-2A and Jason-2 altimeters for sea surface height using GPS buoy in Qinglan, China 被引量:6
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作者 CHEN Chuntao ZHU Jianhua +4 位作者 ZHAI Wanlin YAN Longhao ZHAO Yili HUANG Xiaoqi YANG Weiwei 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2019年第5期1533-1541,共9页
GPS buoy methodology is one of the main calibration methodologies for altimeter sea surface height calibration. This study introduces the results of the Qinglan calibration campaign for the HY-2A and Jason-2 altimeter... GPS buoy methodology is one of the main calibration methodologies for altimeter sea surface height calibration. This study introduces the results of the Qinglan calibration campaign for the HY-2A and Jason-2 altimeters. It took place in two time slices;one was from August to September 2014, and the other was in July 2015. One GPS buoy and two GPS reference stations were used in this campaign. The GPS data were processed using the real-time kinematic (RTK) technique. The fi nal error budget estimate when measuring the sea surface height (SSH) with a GPS buoy was better than 3.5 cm. Using the GPS buoy, the altimeter bias estimate was about -2.3 cm for the Jason-2 Geophysical Data Record (GDR) Version ‘D' and from -53.5 cm to -75.6 cm for the HY-2A Interim Geophysical Data Record (IGDR). The bias estimates for Jason-2 GDR-D are similar to the estimates from dedicated calibration sites such as the Harvest Platform, the Crete Site and the Bass Strait site. The bias estimates for HY-2A IGDR agree well with the results from the Crete calibration site. The results for the HY-2A altimeter bias estimated by the GPS buoy were verifi ed by cross-calibration, and they agreed well with the results from the global analysis method. 展开更多
关键词 HY-2A ALTIMETER CALIBRATION GPS BUOY SEA surface HEIGHT Jason-2 ALTIMETER
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The validation of the significant wave height product of HY-2altimeter–primary results 被引量:8
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作者 CHEN Chuntao ZHU Jianhua +5 位作者 LIN Mingsen ZHAO Yili HUANG Xiaoqi WANG He ZHANG Youguang PENG Hailong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第11期82-86,共5页
The HY-2 satellite was successfully launched on 16 August 2011. The HY-2 significant wave height (SWH) is validated by the data from the South China Sea (SCS) field experiment, National Data Buoy Center (NDBC/ bu... The HY-2 satellite was successfully launched on 16 August 2011. The HY-2 significant wave height (SWH) is validated by the data from the South China Sea (SCS) field experiment, National Data Buoy Center (NDBC/ buoys and Jason-1/2 altimeters, and is corrected using a linear regression with in-situ measurements. Com- pared with NDBC SWH, the HY-2 SWH show a RMS of 0.36 m, which is similar to Jason- 1 and Jason-2 SWH with the RMS of 0.35 m and 0.37 m respectively; the RMS of corrected HY-2 SWH is 0.27 m, similar to 0.27 m and 0.23 m of corrected Jason-1 and Jason-2 SWH. Therefore the accuracy of HY-2 SWH products is close to that of Jason-1/2 SWH, and the linear regression function derived can improve the accuracy of HY-2 SWH products. 展开更多
关键词 ALTIMETER significant wave height VALIDATION linear regression CORRECTION root mean square
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Assessment of the initial sea surface temperature product of the scanning microwave radiometer aboard on HY-2 satellite 被引量:6
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作者 ZHAO Yili ZHU Jianhua +5 位作者 LIN Mingsen CHEN Chuntao HUANG Xiaoqi WANG He ZHANG Youguang PENG Hailong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第1期109-113,共5页
HY-2 satellite is the first satellite for dynamic environmental parameters measurement of China,which was launched on 16th August 2011.A scanning microwave radiometer(RM) is carried for sea surface temperature(SST... HY-2 satellite is the first satellite for dynamic environmental parameters measurement of China,which was launched on 16th August 2011.A scanning microwave radiometer(RM) is carried for sea surface temperature(SST),sea surface wind speed,columnar water vapor and columnar cloud liquid water detection.In this paper,the initial SST product of RM was validated with in-situ data of National Data of Buoy Center(NDBC) mooring and Argo buoy.The validation results indicate the accuracy of RM SST is better than 1.7 C.The comparison of RM SST and WindSat SST shows the former is warmer than the latter at high sea surface wind speed and the difference between these SSTs is depend on the sea surface wind speed.Then,the relationship between the errors of RM SST and sea surface wind speed was analyzed using NDBC mooring measurements.Based on the results of assessment and errors analysis,the suggestions of taking account of the affection of sea surface wind speed and using sea surface wind speed and direction derived from the microwave scatteromter aboard on HY-2 for SST product calibration were given for retrieval algorithm improvement. 展开更多
关键词 validation sea surface temperature HY-2 satellite microwave radiometer
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