A Post-Processing Method for the Removal of Refraction Artifacts in Multibeam Bathymetry Data
A Post-Processing Method for the Removal of Refraction Artifacts in Multibeam Bathymetry Data
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DOI：
10.1080/01490410701438380
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发表时间：
2007-08
期刊：
影响因子：
1.6
通讯作者：
Fanlin Yang;Jiabiao Li;Ziyin Wu;Xianglong Jin;F. Chu;Zhong-Bo Kang
中科院分区：
文献类型：
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作者：
Fanlin Yang;Jiabiao Li;Ziyin Wu;Xianglong Jin;F. Chu;Zhong-Bo Kang
多波束条带测深数据中经常出现声折射伪影。对于平面阵列，外光束中的伪影通常比内光束中的伪影更严重。在3D地形图中，它们显示为平行于血管轨迹的脊。为了缩短测量时间，应尽可能多地使用外波束。因此，应消除折射误差。在本文中，我们提出了一个模型的约化声速剖面，由三个水层。两个上层的声速具有恒定的梯度，并且第三层具有与最底部测量层相同的声速。模型参数的搜索可以基于两个相邻条带的重叠之间的深度差最小的原则。可以使用模型参数相应地重新计算每个梁的水平位置和深度。为了避免陷入局部最优，初始搜索范围根据假设午餐角和旅行时间在每个子区域。通过仿真数据与真实的数据的对比，验证了该方法的有效性。
Sound refraction artifacts are often present in multibeam swath bathymetry data. For a flat array, the artifacts are usually more serious in outer beams than in inner beams. In a 3D topographical mapping they appear as ridges that parallel the tracks of the vessel. To shorten the survey time, the outer beams should be utilized as often as possible. Therefore, the refraction errors should be removed. In this paper, we present a model of reduced sound speed profile that consists of three water layers. The sound speed of the two upper layers has a constant gradient, and the third layer has the same sound speed as the most bottom measured layer. The model parameters can be searched based on the principle of the minimum difference of depth between the overlap of two neighboring swaths. The horizontal position and depth of each beam can be accordingly recalculated using the model parameters. To avoid being trapped in local optimum, the initial search scope is limited according to assumed lunch angle and travel time in each subregion. The method is verified by comparing the simulated and real data.