Sidescan sonar geophysical data offshore of the Lower Mississippi River Delta, Louisiana

In June-July 2024, 831 line-kilometers of sidescan sonar geophysical data were collected in shallow water offshore of the Lower Mississippi River Delta as part of the Mississippi River Delta Transition Initiative (MissDelta) project. This dataset serves as an archive of high- and low-frequency sidescan sonar files in eXtensible Triton Framework (XTF) format, which produces an image of the seafloor within a swath with variable widths. Data were collected using an Edgetech DS2000 towfish instrument that was towed at a depth of 1-3 meters below the water's surface. This instrument collected both sub-bottom geophysical data and sidescan sonar data concurrently. The sidescan sonar data were collected at low frequencies of 100 kHz and high frequencies of 400 kHz. Acoustic energy emitted from the towfish instrument reflects off the seafloor, and the intensity of reflected sound is received by the instrument's transducer and recorded by a computer-based topside unit. As sidescan sonar data were taken along a grid of Chirp geophysical data, sidescan sonar imagery produced by this dataset do not form a mosaic. Positioning data for the sidescan sonar data were collected by a Hemisphere Global Positioning System (GPS) antenna. The layback between the GPS antenna and the towfish was measured at 7.3 meters.