Abstract:

Simultaneous multibeam and phase-bathymetric sidescan sonar data were collected in three of six selected areas. The multibeam used was Reason 7125, and Phase-bathymetric sidescan sonar was Edgetech 4600. Auxiliary data such as position and motion were collected using POS MV system and a secondary C-Nav system. Sound velocity profiles were taken by the portable CastAway system. The data were collected from approximately three to five nautical miles West-South West of Pass Christian Harbor, Mississippi to determine the ability to detect seafloor changes using the repetitive survey with both sonar mounted on poles on the port and starboard sides of the R/V LeMoyne. Close to 200% data overlapping was maintained. The boat was run on the same set of lines during repetitive mapping. This second set of data was collected between 2018-08-23 and 2018-08-24. The data included are the raw multibeam, sidescan, navigation, and sound velocity data, as well as a description of the patch test results and relative instrument offsets on the platform. The gridded sidescan data for all occupations are located in related dataset under GRIIDC Unique Dataset Identifier (UDI): MS.x841.000:0017 (doi: 10.7266/D6WK18XM), while other raw data can be obtained from dataset UDIs: MS.x841.000:0002 (doi: 10.7266/QEY465WM), MS.x841.000:0014 (doi: 10.7266/RNE60WQ2), and MS.x841.000:0016 (doi: 10.7266/3BABAFZK).

Suggested Citation:

Hiroji, Anand. 2020. Repetitive acoustic mapping of oyster reef restoration sites off Pass Christian in Mississippi Sound using multibeam sonar and phase-bathymetric sidescan sonar aboard R/V LeMoyne from 2018-08-23 to 2018-08-24. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/K9ZH3E82

Purpose:

Repeated assessment of changes in bathymetry and sediment in oyster reef restoration projects areas off Pass Christian, Mississippi.

Data Parameters and Units:

Seafloor bathymetry and backscatter intensities, boat motion and position, sound speed profiles.

Methods:

A patch test was performed at the beginning of each survey to calibrate the multibeam sonar (included in the dataset). Periodic sound velocity casts were taken to correct for any sound speed variations. Position and motion data were monitored for accuracy and integrated with the sonar data in real-time. A real-time coverage map was generated to ensure complete coverage of the survey area. Raw data sets were collected for any future processing. The R/V LeMoyne is a thirty-foot vessel temporarily equipped with the instrumentation and towed for the survey.

Instruments:

Portable CastAway system, POS MV system and secondary C-Nav system, Reson 7125 multibeam sonar, Edgetech 4600 Phase-bathymetric sidescan sonar.

Individual Files: