LADCP(Lowered Acoustic Doppler Current Profiler)的底跟踪速度为获取全水深绝对流速剖面提供了多个参考流速。然而,不同底跟踪参考流速得到的绝对流速剖面结果却不相同。针对该问题进行了分析,结果表明:底跟踪观测的样本数及其在总...LADCP(Lowered Acoustic Doppler Current Profiler)的底跟踪速度为获取全水深绝对流速剖面提供了多个参考流速。然而,不同底跟踪参考流速得到的绝对流速剖面结果却不相同。针对该问题进行了分析,结果表明:底跟踪观测的样本数及其在总流速观测样本中的比例随着离底高度的增加而减小;由于观测误差存在,底跟踪观测样本得到的流速剪切和所有流速观测样本得到的流速剪切并不相等,从而导致不同底跟踪参考流速得到的绝对流速结果不同。展开更多
结合CTD/LADCP(Conductivity-Temperature-Depth/Lowed Acoustic Doppler Current Profiler)观测实例,从作业海况、水下单元架构、水下姿态三方面分析研究下放式海洋观测中同轴铠装缆自缠绕/打结状况发现,仪器观测架在布放过程中存在旋...结合CTD/LADCP(Conductivity-Temperature-Depth/Lowed Acoustic Doppler Current Profiler)观测实例,从作业海况、水下单元架构、水下姿态三方面分析研究下放式海洋观测中同轴铠装缆自缠绕/打结状况发现,仪器观测架在布放过程中存在旋转现象,旋转产生的扭力作用于同轴铠装缆;扭力得不到释放,在海况较差的情况下极易造成同轴铠装缆的自缠绕/打结。为解决这些问题,本文进一步提出了一套实用的改进方案,在既保证能够在较差海况下作业、又不减少观测仪器的前提下,改进仪器观测架和同轴铠装缆的连接结构,同时增加机械转环及附属结构。观测实践证明,该方案可以有效避免与CTD/LADCP观测类似的下放式观测中同轴铠装缆因自缠绕造成的“打结”现象的出现,大大提高了现场观测效率,保证了仪器安全和数据顺利传输。该技术源自基本海洋观测实践,可为广大海洋调查工作者提供有益的借鉴。展开更多
The current velocity observation of LADCP(Lowered Acoustic Doppler Current Profiler)has the advantages of a large vertical range of observation and high operability compared with traditional current measurement method...The current velocity observation of LADCP(Lowered Acoustic Doppler Current Profiler)has the advantages of a large vertical range of observation and high operability compared with traditional current measurement methods,and is being widely used in the field of ocean observation.Shear and inverse methods are now commonly used by the international marine community to process LADCP data and calculate ocean current profiles.The two methods have their advantages and shortcomings.The shear method calculates the value of current shear more accurately,while the accuracy in an absolute value of the current is lower.The inverse method calculates the absolute value of the current velocity more accurately,but the current shear is less accurate.Based on the shear method,this paper proposes a layering shear method to calculate the current velocity profile by“layering averaging”,and proposes corresponding current calculation methods according to the different types of problems in several field observation data from the western Pacific,forming an independent LADCP data processing system.The comparison results have shown that the layering shear method can achieve the same effect as the inverse method in the calculation of the absolute value of current velocity,while retaining the advantages of the shear method in the calculation of a value of the current shear.展开更多
针对 L ADCP这一崭新而又特殊的海流观测技术 ,系统地介绍了 L ADCP/CTD捆绑式测量、罗盘标定、测量设置和附加信息获取等 L ADCP观测中的主要技术问题。在对 L ADCP瓦迭式资料特点进行研究的基础上 ,阐释了 L ADCP资料后处理的关键技...针对 L ADCP这一崭新而又特殊的海流观测技术 ,系统地介绍了 L ADCP/CTD捆绑式测量、罗盘标定、测量设置和附加信息获取等 L ADCP观测中的主要技术问题。在对 L ADCP瓦迭式资料特点进行研究的基础上 ,阐释了 L ADCP资料后处理的关键技术 :首先进行 L ADCP资料初处理和声速剖面校正 ,利用同 ping剖面内相邻两水层的 L ADCP测量值之差等于两水层的真实速度之差这一特性 ,把 L ADCP的所有测量值转化为垂向切变流速 ,求出水柱内各水层的垂向切变率 ,对其按照一定的积分顺序进行深度积分 ,得到水柱内各水层相对于参考层的相对速度 ,利用底跟踪信息可以较直接地求出参考层的速度 ,也可以根据测量过程中 L ADCP和测船相对位置在入水时和出水时保持不变这一基本成立的假定通过 GPS信息求出参考层的速度 ,从而得到整个水柱内各水层的绝对流速。为了提高处理结果的准确度 。展开更多
文摘LADCP(Lowered Acoustic Doppler Current Profiler)的底跟踪速度为获取全水深绝对流速剖面提供了多个参考流速。然而,不同底跟踪参考流速得到的绝对流速剖面结果却不相同。针对该问题进行了分析,结果表明:底跟踪观测的样本数及其在总流速观测样本中的比例随着离底高度的增加而减小;由于观测误差存在,底跟踪观测样本得到的流速剪切和所有流速观测样本得到的流速剪切并不相等,从而导致不同底跟踪参考流速得到的绝对流速结果不同。
文摘结合CTD/LADCP(Conductivity-Temperature-Depth/Lowed Acoustic Doppler Current Profiler)观测实例,从作业海况、水下单元架构、水下姿态三方面分析研究下放式海洋观测中同轴铠装缆自缠绕/打结状况发现,仪器观测架在布放过程中存在旋转现象,旋转产生的扭力作用于同轴铠装缆;扭力得不到释放,在海况较差的情况下极易造成同轴铠装缆的自缠绕/打结。为解决这些问题,本文进一步提出了一套实用的改进方案,在既保证能够在较差海况下作业、又不减少观测仪器的前提下,改进仪器观测架和同轴铠装缆的连接结构,同时增加机械转环及附属结构。观测实践证明,该方案可以有效避免与CTD/LADCP观测类似的下放式观测中同轴铠装缆因自缠绕造成的“打结”现象的出现,大大提高了现场观测效率,保证了仪器安全和数据顺利传输。该技术源自基本海洋观测实践,可为广大海洋调查工作者提供有益的借鉴。
基金The National Natural Science Foundation of China under contract No.42206033the Marine Geological Survey Program of China Geological Survey under contract No.DD20221706+1 种基金the Research Foundation of National Engineering Research Center for Gas Hydrate Exploration and Development,Innovation Team Project,under contract No.2022GMGSCXYF41003the Scientific Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources,under contract No.JG2006.
文摘The current velocity observation of LADCP(Lowered Acoustic Doppler Current Profiler)has the advantages of a large vertical range of observation and high operability compared with traditional current measurement methods,and is being widely used in the field of ocean observation.Shear and inverse methods are now commonly used by the international marine community to process LADCP data and calculate ocean current profiles.The two methods have their advantages and shortcomings.The shear method calculates the value of current shear more accurately,while the accuracy in an absolute value of the current is lower.The inverse method calculates the absolute value of the current velocity more accurately,but the current shear is less accurate.Based on the shear method,this paper proposes a layering shear method to calculate the current velocity profile by“layering averaging”,and proposes corresponding current calculation methods according to the different types of problems in several field observation data from the western Pacific,forming an independent LADCP data processing system.The comparison results have shown that the layering shear method can achieve the same effect as the inverse method in the calculation of the absolute value of current velocity,while retaining the advantages of the shear method in the calculation of a value of the current shear.
文摘针对 L ADCP这一崭新而又特殊的海流观测技术 ,系统地介绍了 L ADCP/CTD捆绑式测量、罗盘标定、测量设置和附加信息获取等 L ADCP观测中的主要技术问题。在对 L ADCP瓦迭式资料特点进行研究的基础上 ,阐释了 L ADCP资料后处理的关键技术 :首先进行 L ADCP资料初处理和声速剖面校正 ,利用同 ping剖面内相邻两水层的 L ADCP测量值之差等于两水层的真实速度之差这一特性 ,把 L ADCP的所有测量值转化为垂向切变流速 ,求出水柱内各水层的垂向切变率 ,对其按照一定的积分顺序进行深度积分 ,得到水柱内各水层相对于参考层的相对速度 ,利用底跟踪信息可以较直接地求出参考层的速度 ,也可以根据测量过程中 L ADCP和测船相对位置在入水时和出水时保持不变这一基本成立的假定通过 GPS信息求出参考层的速度 ,从而得到整个水柱内各水层的绝对流速。为了提高处理结果的准确度 。
