Array Parameters. In SWellEx-96 Experiment Acoustic Data

Arrays Four acoustic sensor arrays were deployed in SWellEx-96: a vertical line array (VLA), a tilted line array (TLA), a horizontal line array (HLA North), and a second horizontal line array (HLA South). Both the VLA and TLA's data were recorded aboard the R/P FLIP (FLIP's Position: 32d40.254' N 117d21.635' W). The two HLAs' data were recorded at an onshore recording station. To download text files containing information about entire arrays, select any of the “Array positions” components. Element Positions To download tab-delimited, ASCII files of element positions, select any of the “Element positions” components. The VLA was not purely vertical. It had a small tilt of 2 or 3 degrees from vertical toward the west, which was determined via conventional matched field processing using the highest level tonal set and known source locations. Corrections to element positions can be made using these array tilt estimates. Since the source track is not a true radial track, note that the apparent array tilt (from the perspective of the source) changes over time, i.e., range. The data files under Event S5 and Event S59 have the channels reversed. Process the data with the array positions reversed. So channel 1 will have a depth of 94.125 m and channel 21 (of data file) will have a depth of 212.25 m. The TLA had a 45-47 deg tilt. Both matched field processing and tilt sensors were used to confirm the array tilt. The bow in the array was negligible. The HLA North array is a 240 m aperture horizontal array deployed on the seafloor. Line of bearing from the first element to the last element is 34.5 deg clockwise from North. There is a slight bow (~13 m) in the array. Select component, “Plots of array elements: HLA North,” for a plot of element positions. The HLA South array is a 255 m aperture horizontal array deployed on the seafloor. The line of bearing from the first element to the last element is -43.0 deg with respect to North (positive values are clockwise). Select component, “Plots of array elements: HLA South,” for a plot of element positions.阵列 本次SWellEx-96实验中共部署了四套声学传感器阵列：垂直线列阵（VLA, Vertical Line Array）、倾斜线列阵（TLA, Tilted Line Array）、北方向水平线列阵（HLA North）以及第二套水平线列阵（HLA South）。VLA与TLA的采集数据均由R/P FLIP平台（FLIP平台坐标：32°40.254′ N，117°21.635′ W）搭载获取。两套HLA的采集数据则来自陆上观测站。如需下载包含整套阵列信息的文本文件，可任选“阵列位置”组件进行获取。 阵元位置 如需下载阵元位置的制表符分隔ASCII文件，可任选“阵元位置”组件进行获取。 垂直线列阵并非严格垂直，其相对垂直面向西存在2°至3°的微小倾斜，该倾斜量通过采用最高阶单频信号组与已知震源位置的常规匹配场处理方法确定。可基于该阵列倾斜估计值对阵元位置进行校正。由于震源轨迹并非严格的径向轨迹，需注意：从震源视角观测到的表观阵列倾斜度会随时间（即传播距离）发生变化。事件S5与事件S59对应的数据文件中通道顺序发生反转，处理数据时需调换阵列位置。此时通道1对应水深94.125 m，数据文件中的通道21对应水深212.25 m。 倾斜线列阵的倾斜角度为45°至47°，通过匹配场处理与倾斜传感器共同确认了该阵列倾斜量。阵列存在的微小弯曲可忽略不计。 北方向水平线列阵为部署于海底、孔径240 m的水平阵列，首阵元至末阵元的方位角为北偏东34.5°（顺时针方向）。阵列存在约13 m的微小弯曲。如需查看阵元位置分布图，可选择“阵列阵元绘图：HLA North”组件。 南方向水平线列阵为部署于海底、孔径255 m的水平阵列，首阵元至末阵元的方位角为北偏西43.0°（正值代表顺时针方向）。如需查看阵元位置分布图，可选择“阵列阵元绘图：HLA South”组件。