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1.
多波束水深测量中受潮汐因素的影响,测量垂直基准是变化的,具有瞬时性。传统多波束测量,需在测区内设立一个或多个验潮站进行同步水位观测,最终将水深归算到深度基准面上。针对多波束水深测量中垂直基准转换的复杂性问题,文中基于地球重力场模型,结合测区内实测的GNSS/水准数据,通过插值算法建立了测区范围内似大地水准面精化模型,构建了多波束无验潮水深测量的垂直基准转换模型。通过实例表明,该方法有效地消除了潮汐、动态吃水及涌浪等因素影响,直接获取深度基准面的水深值,提高工作效率,可满足近岸多波束水深测量的工作需求。  相似文献   

2.
为了改善多波束声纳的分辨率,提出了一种基于相干原理的测深新算法,对每一个波束脚印内的信号进行相干处理,获得了大量的海底深度值。在此基础上,采用新算法对仿真数据和某型号多波束测深声纳湖上实验数据进行处理。结果表明,相对于传统多波束测深算法,该算法可显著提高声纳海底测量的分辨率,获得大量的海底深度测量值。  相似文献   

3.
The filtering and compressing of outer beams to multibeam bathymetric data   总被引:1,自引:0,他引:1  
Some errors and noises are often present in multibeam swath bathymetric data. Echo detection error (EDE) is one of the main errors. It causes the depth error to become bigger in outer beams and looks like sound refraction. But depth errors due to EDEs have a trumpet-shaped appearance, instead of a curved appearance that is caused by the sound refraction errors. EDEs, including systematic acoustic signal detection errors and internal noises, cannot be removed during the correction of sound refraction. It causes depth inconsistencies between adjacent swaths and degrades precision of outer beams. Sometimes, the bathymetric errors caused by EDEs do not even meet the requirements of IHO (International Hydrographic Organization). Therefore, a post-processing method is presented to minimize the EDEs by filtering outliers and compressing outer beams of multibeam bathymetric data. The outliers caused by internal noises are removed by an automatic filter algorithm first. Then the outer beams are compressed to reduce systematic acoustic signal detection errors according to their depths, the calculated depth line and standard deviations (SDs). The automatic filter process is important for calculating the depth line. The selection of inner beams to calculate the average SD of beam depths is crucial to achieving compressing goals. The quality of final bathymetric data in outer beams can be improved by these steps. The method is verified by a field test.  相似文献   

4.
以多波束精确的水深数据为参照源,采用原始回波时间对多波束测深数据与其同源声纳数据进行匹配,从而获得高精度和高分辨率的海底影像数据,并避免了传统声纳图像处理过程中斜距改正所带来的几何形变。匹配结果采用光照图输出,并与三维水深图、原始声纳图像和CARIS处理后的声纳图像进行比较分析。该方法有效地提高了多波束数据的利用率,增强了对海底地形的探测分辨率。  相似文献   

5.
Multibeam bathymetric system (MBS) has been widely applied in the marine surveying for providing high-resolution seabed topography. However, some factors degrade the precision of bathymetry, including the sound velocity, the vessel attitude, the misalignment angle of the transducer and so on. Although these factors have been corrected strictly in bathymetric data processing, the final bathymetric result is still affected by their residual errors. In deep water, the result usually cannot meet the requirements of high-precision seabed topography. The combined effect of these residual errors is systematic, and it’s difficult to separate and weaken the effect using traditional single-error correction methods. Therefore, the paper puts forward a new method for weakening the effect of residual errors based on the frequency-spectrum characteristics of seabed topography and multibeam bathymetric data. Four steps, namely the separation of the low-frequency and the high-frequency part of bathymetric data, the reconstruction of the trend of actual seabed topography, the merging of the actual trend and the extracted microtopography, and the accuracy evaluation, are involved in the method. Experiment results prove that the proposed method could weaken the combined effect of residual errors on multibeam bathymetric data and efficiently improve the accuracy of the final post-processing results. We suggest that the method should be widely applied to MBS data processing in deep water.  相似文献   

6.
多波束测深质量评价方法分析   总被引:1,自引:0,他引:1  
肖波  盛堰  刘胜旋 《海洋测绘》2013,33(3):56-58
利用Caris多波束处理软件、Global Mapper图形处理和Surfer处理软件中三角网网格化的方法来处理多波束水深数据,从整个测量范围来做水深准确度检验,由传统的水深数据处理线统计发展到面统计,能更有效的评价多波束资料的质量,提高质量控制的水平。  相似文献   

7.
In high-resolution, shallow-water seismic surveys, correction for water-column height variations caused by tides, weather, and currents is an important part of data processing. In this study, we present a very simple method of correction for profile-length (i.e., long-wavelength) water-column height variations for high-resolution seismic data using a reference bathymetric grid. First, the difference between the depth of the seafloor picked from seismic data and the bathymetry from the bathymetric grid is computed at the locations where the shot points of seismic profiles and the bathymetric grid points are collocated or closest. Then, the results are gridded and smoothed to obtain the profile-length water-column height variations for the survey area. Next, the water-column height variations for each seismic profile are extracted from the smoothed grid and converted to two-way traveltimes. The corrections for the remaining mis-ties at the intersections, computed within a circular region around each tie shot point, are added to the corrections for the water-column height variations. The final, mistie corrected water-column height corrections are loaded to the SEGY trace header of seismic data as a total static. We applied this method to the sparker data acquired from the shallow-water area off the western-central part of Korea where the tidal range is over 7 m. The corrections for water-column height variations range from -10 to 4 m with a median value of about -2 m. Large corrections occur locally between and near the islands probably due to the amplification and shortening in tidal wavelength caused by rapid shoaling toward the islands.  相似文献   

8.
This paper examines the potential for remote classification of seafloor terrains using a combination of quantitative acoustic backscatter measurements and high resolution bathymetry derived from two classes of sonar systems currently used by the marine research community: multibeam echo-sounders and bathymetric sidescans sonar systems. The high-resolution bathymetry is important, not only to determine the topography of the area surveyed, but to provide accurate bottom slope corrections needed to convert the arrival angles of the seafloor echoes received by the sonars into true angles of incidence. An angular dependence of seafloor acoustic backscatter can then be derived for each region surveyed, making it possible to construct maps of acoustic backscattering strength in geographic coordinates over the areas of interest. Such maps, when combined with the high-resolution bathymetric maps normally compiled from the data output by the above sonar systems, could be very effective tools to quantify bottom types on a regional basis, and to develop automatic seafloor classification routines.  相似文献   

9.
Full-coverage multibeam bathymetric maps of the southern section of the Juan de Fuca Plate, also known as the Gorda Plate, are presented. The bathymetric maps represent the compilation of multibeam surveys conducted by the National Oceanic and Atmospheric Administration during the last 20 yrs, and illustrate the complex tectonic, volcanic, and geomorphologic features as well as the intense deformation occurring within this region. The bathymetric data have revealed several major, previously unmapped midplate faults. A series of gently curving faults are apparent in the Gorda Plate, with numerous faults offsetting the Gorda Plate seafloor. The multibeam surveys have also provided a detailed view of the intense deformation occurring within the Gorda Plate. A preliminary deformation model estimated from basement structure is discussed, where the southern part of the plate (south of ∼42°30′ N) seems to be deforming through a series of left-lateral strike-slip faults, while the northern section appears to be moving passively with the rest of the Juan de Fuca Plate. The bathymetry also demonstrates the Mendocino and Eel Canyons are prominent morphologic features in the northern California margin. These canyons are active depositional features with a large sediment fan present at the mouths of both the Mendocino and Eel canyons. The depositional lobes of these fan(s) are evident in the bathymetry, as are the turbidite channels that have deposited sediment along the fans over time. The Trinidad Canyon is readily evident in the margin morphology as well, with a large (∼10 km) plunge pool formed at the mouth of the canyon as it enters the Gorda Plate sediments. This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   

10.
针对上海世博会对黄浦江航道核心水域高精度海底地形的需求,采用SeaBat8125多波束测深系统对该区域进行了全覆盖测量.通过潮汐基准面归算、潮汐改正精度内符合检验、原始数据各项改正、除噪处理及测深误差分析等几个步骤,得到基于吴淞零点的最终水深成果.各项检验表明,此次多波束测深成果质量满足实际需求.  相似文献   

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