共查询到18条相似文献,搜索用时 703 毫秒
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多波束测深系统声速校正 总被引:13,自引:0,他引:13
海水声速是多波束测深系统进行水深测量的基本参数之一,声速剖面正确与否直接影响测量结果的精度和可靠性。声速校正为多波束测深系统提供了正确的声速剖面,根据声速剖面垂向上的变化规律,对原始声速数据进行科学采点,运用软件方法或实验方法对声速剖面进行编辑获得声速数据,最终取得合理可靠的水深值。这里对南海SA12试验区采集的声速资料进行了分析,以SeaBeam2100多波速测深系统为例,对声速校正的技术方法进行了探讨。 相似文献
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多波束测深系统声速校正 总被引:5,自引:0,他引:5
海水声速是多波束测深系统进行水深测量的基本参数之一,声速剖面正确与否直接影响测量结果的精度和可靠性,本文阐述了声对多波束水深测量的影响机理,并通过对南海SA12试验区采集的声速资料的分析,以SeaBeam2100多波束测深系统为例,对声速校正的技术方法进行了探讨。 相似文献
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经验正交函数(EOF)是描述声速剖面的有效基函数,通常只需要前几阶EOF即可较为精确地表示声速剖面。但使用EOF重构的声速剖面进行多波束测量声速改正时,选取的阶次未必满足多波束测深精度要求。针对此问题,首先介绍了EOF表示声速剖面的原理及流程,然后以北海某区域实测声速剖面数据为例,分析了不同阶次EOF拟合声速剖面误差以及不同阶次EOF拟合声速剖面对多波束测深的影响,最后结合NOAA对多波束测量声速剖面误差造成的水深限差要求确定EOF阶次,实现了在满足多波束测深精度的同时,合理确定EOF阶次的目的。 相似文献
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在深远海海域开展多波束水深测量时,受海上苛刻作业条件等多种影响,获取全深度声速剖面往往比较困难。首先联合WOA2018温盐模型和多个站位CTD、XCTD实测温盐剖面资料开展了全深度声速剖面重构,进而使用三组来源不同的全深度声速剖面开展了多波束测深声速改正对比分析。从试验结果看,这几组声速剖面对多波束测深精度的影响基本一致。特别是当假定CTD站位采用XCTD设备并由此推算深度大于1099m的温盐及声速剖面时,多波束测深的声速改正结果也能满足海底地形成果的质量要求。 相似文献
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我们开发了一套名为“MB-SEystem”的新软件包,用来处理和显示由R/V Mau-rice Ewing船采集的Hdrosweep DS多波束数据,这套新软件所包含的工具有:模式化声速剖面;根据声速剖面,利用射线追踪,由声波传播时间计算多波束测深值;对多波速测深值的人工交互和自动编辑;以及运算和显示多波速数据的其它各种工龄,一个模块化的输入/输出库允许MB-system程序存取和运算数据,这些数据可以是任何一种刈幅成图声纳数据格式所支持的数据,它可以收以下设备采集;Hdrosweep DS、“古典式”SeaBeam、SeaBeam2000、SeaBesm2100、H-MR1、Simrad EMl2及其它声纳设备。本文提供了一个利用该软件对最近由R/V Maurice Ewing船采集的Hydrosweep数据进行处理的应用实例。 相似文献
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声速是影响多波束勘测精度的重要的外部因素,它决定着声线跟踪的精度,并最终影响到测深精度。由于停船投放CTD时间成本比较高,探索经济高效的远海走航式多波束水深测量,特别是航渡测量期间的声速剖面获取方法成为现场测量人员急需解决的问题。在对HYCOM/WOA13数据与现场CTD数据进行了数据偏差分布、相关性等比对,验证HYCOM/WOA13数据适用性的基础上,提出了基于HYCOM模式数据、WOA13同化数据及单点历史CTD数据与现场XCTD/XBT多源组合的远海走航式多波束水深测量声速剖面获取方法。对比表明,该多源组合的声速剖面能较好反映施测位置的声速剖面情况,该方法对提高远海水深测量的精度和经济效益具有一定的借鉴意义。 相似文献
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We have developed a new software package, called MB-System, for processing and display of Hydrosweep DS multibeam data on the R/V Maurice Ewing. The new software includes tools for modeling water sound velocity profiles, calculating multibeam bathymetry from travel time values by raytracing through a water sound velocity profile, interactive and automatic editing of multibeam bathymetry, as well as a variety of tools for the manipulation and display of multibeam data. A modular input/output library allows MB-System programs to access and manipulate data in any of a number of supported swath-mapping sonar data formats, including data collected on Hydrosweep DS, Sea-Beam Classic, SeaBeam 2000, SeaBeam 2100, H-MR1, Simrad EM12, and other sonars. Examples are presented of the software's application to Hydrosweep data recently collected on the R/V Maurice Ewing. 相似文献
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Precise Multibeam Acoustic Bathymetry 总被引:7,自引:0,他引:7
The maximum error in ocean depth measurement as specified by the International Hydrographic Organization is 1% for depth greater than 30m. Current acoustic multibeam bathymetric systems used for depth measurement are subject to errors from various sources which may significantly exceed this limit. The lack of sound speed profiles may be one significant source of error. Because of the limited ability of sound speed profile measurement, depth values are usually estimated using an assumed profile. If actual sound speed profiles are known, depth estimate errors can be corrected using ray-tracing methods. For depth measurements, the calculation of the location at which a sound pulse impinges on the sea bottom varies with the variation of the sound speed profile. We demonstrate that this location is almost unchanged for a family of sound speed profiles with the same surface value and the same area under them. Based on this observation, we can construct a simple constant-gradient equivalent sound speed profile to correct errors. Compared with ray-tracing methods, the equivalent sound speed profile method is more efficient. If a vertical depth is known (or independently measured), then depth correction for a multibeam system can be accomplished without knowledge of the actual sound speed profile. This leads to a new type of precise acoustic multibeam bathymetric system. 相似文献
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The maximum error in ocean depth measurement as specified by the International Hydrographic Organization is 1% for depth greater than 30m. Current acoustic multibeam bathymetric systems used for depth measurement are subject to errors from various sources which may significantly exceed this limit. The lack of sound speed profiles may be one significant source of error. Because of the limited ability of sound speed profile measurement, depth values are usually estimated using an assumed profile. If actual sound speed profiles are known, depth estimate errors can be corrected using ray-tracing methods. For depth measurements, the calculation of the location at which a sound pulse impinges on the sea bottom varies with the variation of the sound speed profile. We demonstrate that this location is almost unchanged for a family of sound speed profiles with the same surface value and the same area under them. Based on this observation, we can construct a simple constant-gradient equivalent sound speed profile to correct errors. Compared with ray-tracing methods, the equivalent sound speed profile method is more efficient. If a vertical depth is known (or independently measured), then depth correction for a multibeam system can be accomplished without knowledge of the actual sound speed profile. This leads to a new type of precise acoustic multibeam bathymetric system. 相似文献
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An experiment aboard the Scripps Institution of Oceanography's RV Thomas Washington has demonstrated the seafloor mapping advantages to be derived from combining the high-resolution bathymetry of a multibeam echo-sounder with the sidescan acoustic imaging plus wide-swath bathymetry of a shallow-towed bathymetric sidescan sonar. To a void acoustic interference between the ship's 12-kHz Sea Beam multibeam echo-sounder and the 11-12-kHz SeaMARC II bathymetric sidescan sonar system during simultaneous operations, Sea Beam transmit cycles were scheduled around SeaMARC II timing events with a sound source synchronization unit originally developed for concurrent single-channel seismic, Sea Beam, and 3.5-kHz profile operations. The scheduling algorithm implemented for Sea Beam plus SeaMARC II operations is discussed, and the initial results showing their combined seafloor mapping capabilities are presented 相似文献
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A computer code that simulates multibeam echo‐sounding over realistic (three‐dimensional) bathymetry was used to compare available sounding systems. Two‐dimensional modeling dealt with the resolution of seafloor bathymetry and with the effect of postprocessing algorithms for some typical multibeam systems. The 2‐D bathymetric inputs were idealized bottom features. Three‐dimensional modeling dealt with the gross character of the seafloor, as detected by echo‐sounding systems. The 3‐D bathymetric inputs were realizations of terrain generated by a stochastic model of seafloor roughness. Three‐dimensional modeling indicated that the sounding system may slightly shift the location of peaks within the beam footprint. In addition, the simulated measurements were more sensitive to low‐wavenumber features (i.e., large‐scale roughness) than to high‐wavenumber features (i.e., small‐scale roughness). Resolution gradually decreased with increasing distance from centerline, due to the increasing footprint size of beams at increasing angular distance from the vertical. Lineated terrain was also smoothed by simulated echo‐sounding; lineations may indeed remain undetected if sounding system parameters are not properly selected. Inversion of the simulated measurements indicated that echo‐sounding measurements are dependent not only on the characteristics of the sounding system itself, but on other factors such as the character of the roughness and the orientation of the survey relative to the strike of lineations. The modeling technique provides a way to quantify the system response of a multibeam echo‐sounding system. This work resulted in recommendations as to the most appropriate system for an application in an area of rough bathymetry, and it led to the establishment of criteria for comparing multibeam systems in future applications. 相似文献