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.