The acoustic Doppler current profilers(ADCP)as a new type of flow measuring equipment,can measure the flow velocity of the channel section directly.ADCP has the advantages of short measuring time and wide measuring ra...The acoustic Doppler current profilers(ADCP)as a new type of flow measuring equipment,can measure the flow velocity of the channel section directly.ADCP has the advantages of short measuring time and wide measuring range.The traditional ADCP processing system uses analog method to realize demodulation and filtering,which will introduce extra errors.While digital processing system will greatly increase the computation and slow down the speed of data processing.To solve this problem,an efficient real-time broadband ADCP digital signal processing system is proposed based on the low computational cascade integrator comb(CIC)cascade and interpolated second-order polynomial(ISOP)filter banks.The digital in-phase and quadrature(IQ)demodulation,CIC filter banks,and complex autocorrelation operation steps are cascaded with a pipelined method in the system,which greatly improves the system operating speed while avoiding the high memory occupation of non-real-time systems.展开更多
文章介绍了一种高频采集、数字解调滤波的通用型高频宽带声学多普勒流速剖面仪(Acoustic Doppler Current Profilers,ADCP)信号处理系统的设计和实现过程。该系统以现场可编程逻辑门阵列(Field Programmable Gate Array,FPGA)+数字信号...文章介绍了一种高频采集、数字解调滤波的通用型高频宽带声学多普勒流速剖面仪(Acoustic Doppler Current Profilers,ADCP)信号处理系统的设计和实现过程。该系统以现场可编程逻辑门阵列(Field Programmable Gate Array,FPGA)+数字信号处理器(Digital Signal Processor,DSP)+低功耗单片机(Mixed Signal Processor 430,MSP430)为架构平台,利用三者在信号处理领域的不同优势,采用软硬件协同设计的方式,解决了高频ADCP高采样率、高数据处理能力及低功耗的应用需求,在保证数据处理速度的基础上实现了相位的严格正交,且通过参数化配置实现了多频段、多功能的通用性设计,可适用于不同频段的走航式及自容式ADCP中。经湖上试验验证,该系统测速精度高,性能稳定可靠,达到了预期的设计指标。该系统的软硬件划分方式对其他高频海洋设备的研制具有一定的参考价值。展开更多
The acoustic Echo Intensity (EI) was recorded with 38k shipborne AcousticDoppler Current Profiler (AD-CP) in the Western Pacific in four cruises between Sept. 2001 and Oct.2002. The main Deep Scattering Layer (DSL) wa...The acoustic Echo Intensity (EI) was recorded with 38k shipborne AcousticDoppler Current Profiler (AD-CP) in the Western Pacific in four cruises between Sept. 2001 and Oct.2002. The main Deep Scattering Layer (DSL) was observed at 400m-600 m depth in the four cruises. Thelatitudinal variation of the main DSL, which has high level of back-scatter strength (BS) at highlatitude, is prominent during both nighttime and daytime. The influences of environmental conditionson the DSL are discussed. Since high-oxygen water in the north is a friendly environment of marineanimals which form the main DSL, more animals are expected to aggregate in the 400dbars-600dbarslayer in the north. Dissolved Oxygen (DO) is the principal factor that causes the main DSL to varywith latitude, and its spatial distributions result from formation and transport of North PacificIntermediate Water (NPIW).展开更多
声学多普勒流速剖面仪(Acoustic Doppler Current Profiler,ADCP)对河流进行流量测量时,ADCP一般采用底跟踪模式(以河底为参考系)获得流速、断面面积,进而获得当前流域的流量,但当河流存在大量走沙(“动底”)情况时,底跟踪速度缺少顺水...声学多普勒流速剖面仪(Acoustic Doppler Current Profiler,ADCP)对河流进行流量测量时,ADCP一般采用底跟踪模式(以河底为参考系)获得流速、断面面积,进而获得当前流域的流量,但当河流存在大量走沙(“动底”)情况时,底跟踪速度缺少顺水流分量,致使底跟踪轨迹向上游偏移底跟踪速度偏小,进而导致流量偏小。文章通过对动底原理进行分析、对动底测量方法中的回路法进行研究,提出一种基于GGA的全球定位信息系统(Global Positioning System,GPS)模式下平均动底速度测量方法以及两种动底流量补偿方法,并利用实测数据进行分析验证,结果表明本文提出的动底速度测量方法及动底流量补偿方法对“动底”检测与补偿有显著的效果。展开更多
Based on measured hydrological data by using ship-mounted Acoustic Doppler Current Profiler （ADCP） instrument, we analyzed shapes of river cross sections of the middle Yangtze River basin （mainly focusing on Makou ...Based on measured hydrological data by using ship-mounted Acoustic Doppler Current Profiler （ADCP） instrument, we analyzed shapes of river cross sections of the middle Yangtze River basin （mainly focusing on Makou and Tianjiazhen river reach）. Hydrodynamic properties of river channels were also discussed. The research results indicate that nonlinear relationships can be identified between river-width/river-depth ratio （W/D ratio）, sizes of cross section and mean flow velocity. Positive relations are detected between W/D ratio and mean flow velocity when W/D〈1; and negative relations are observed when W/D〉1. Adverse relationships can be obtained between W/D ratio and cross-section area. Geomorphologic and geologic survey indicates different components of river banks in the wider and narrower river reaches respectively. These may be the main driving factors causing unique hydrological properties of river channels in the middle Yangtze River basin. Narrower river cross sections tend to raise water level in the upstream river reach near narrower river channel, giving rise to backwater effects. River knots can cause serious backwater effects, which is harmful for flood mitigation. However river knots will also stabilize river channel and this will be beneficial for river channel management. The results of this paper may be helpful for flood mitigation and river channel management in the middle Yangtze River basin.展开更多
According to analysis on field data obtained by ADCP （Acoustic Doppler Current Profiler）, the flow regime of the Yangtze River Estuary is studied by use of a 3-D numerical model. The flow field characteristics, unde...According to analysis on field data obtained by ADCP （Acoustic Doppler Current Profiler）, the flow regime of the Yangtze River Estuary is studied by use of a 3-D numerical model. The flow field characteristics, under the influence of Coriolis force, saltwater intrusion and freshwater inflow and tidal current interaction, are depicted in details. The main driving forces and some important effective factors of lateral, longitudinal and horizontal circulation are also analyzed.展开更多
文摘The acoustic Doppler current profilers(ADCP)as a new type of flow measuring equipment,can measure the flow velocity of the channel section directly.ADCP has the advantages of short measuring time and wide measuring range.The traditional ADCP processing system uses analog method to realize demodulation and filtering,which will introduce extra errors.While digital processing system will greatly increase the computation and slow down the speed of data processing.To solve this problem,an efficient real-time broadband ADCP digital signal processing system is proposed based on the low computational cascade integrator comb(CIC)cascade and interpolated second-order polynomial(ISOP)filter banks.The digital in-phase and quadrature(IQ)demodulation,CIC filter banks,and complex autocorrelation operation steps are cascaded with a pipelined method in the system,which greatly improves the system operating speed while avoiding the high memory occupation of non-real-time systems.
文摘文章介绍了一种高频采集、数字解调滤波的通用型高频宽带声学多普勒流速剖面仪(Acoustic Doppler Current Profilers,ADCP)信号处理系统的设计和实现过程。该系统以现场可编程逻辑门阵列(Field Programmable Gate Array,FPGA)+数字信号处理器(Digital Signal Processor,DSP)+低功耗单片机(Mixed Signal Processor 430,MSP430)为架构平台,利用三者在信号处理领域的不同优势,采用软硬件协同设计的方式,解决了高频ADCP高采样率、高数据处理能力及低功耗的应用需求,在保证数据处理速度的基础上实现了相位的严格正交,且通过参数化配置实现了多频段、多功能的通用性设计,可适用于不同频段的走航式及自容式ADCP中。经湖上试验验证,该系统测速精度高,性能稳定可靠,达到了预期的设计指标。该系统的软硬件划分方式对其他高频海洋设备的研制具有一定的参考价值。
文摘The acoustic Echo Intensity (EI) was recorded with 38k shipborne AcousticDoppler Current Profiler (AD-CP) in the Western Pacific in four cruises between Sept. 2001 and Oct.2002. The main Deep Scattering Layer (DSL) was observed at 400m-600 m depth in the four cruises. Thelatitudinal variation of the main DSL, which has high level of back-scatter strength (BS) at highlatitude, is prominent during both nighttime and daytime. The influences of environmental conditionson the DSL are discussed. Since high-oxygen water in the north is a friendly environment of marineanimals which form the main DSL, more animals are expected to aggregate in the 400dbars-600dbarslayer in the north. Dissolved Oxygen (DO) is the principal factor that causes the main DSL to varywith latitude, and its spatial distributions result from formation and transport of North PacificIntermediate Water (NPIW).
基金National Natural Science Foundation of China,No.40701015Key Project of National Natural Science Foundation of China,No.40730635
文摘Based on measured hydrological data by using ship-mounted Acoustic Doppler Current Profiler （ADCP） instrument, we analyzed shapes of river cross sections of the middle Yangtze River basin （mainly focusing on Makou and Tianjiazhen river reach）. Hydrodynamic properties of river channels were also discussed. The research results indicate that nonlinear relationships can be identified between river-width/river-depth ratio （W/D ratio）, sizes of cross section and mean flow velocity. Positive relations are detected between W/D ratio and mean flow velocity when W/D〈1; and negative relations are observed when W/D〉1. Adverse relationships can be obtained between W/D ratio and cross-section area. Geomorphologic and geologic survey indicates different components of river banks in the wider and narrower river reaches respectively. These may be the main driving factors causing unique hydrological properties of river channels in the middle Yangtze River basin. Narrower river cross sections tend to raise water level in the upstream river reach near narrower river channel, giving rise to backwater effects. River knots can cause serious backwater effects, which is harmful for flood mitigation. However river knots will also stabilize river channel and this will be beneficial for river channel management. The results of this paper may be helpful for flood mitigation and river channel management in the middle Yangtze River basin.
基金Funded by the Key Project of the National Natural Science Foundation of China (Grant No50339010)
文摘According to analysis on field data obtained by ADCP （Acoustic Doppler Current Profiler）, the flow regime of the Yangtze River Estuary is studied by use of a 3-D numerical model. The flow field characteristics, under the influence of Coriolis force, saltwater intrusion and freshwater inflow and tidal current interaction, are depicted in details. The main driving forces and some important effective factors of lateral, longitudinal and horizontal circulation are also analyzed.
