Sub-bottom Chirp data (SEG-Y format) from eastern Long Island Sound (2024, 2025)

This data set presents processed sub-bottom data files that were collected in eastern Long Island Sound in August 2024 and May 2025 using R/V Pritchard. The sub-bottom data was acquired with a towed EdgeTech 3400-OTS Chirp system using a sweep frequency of 2-16kHz. The survey was made up of individual north-south-trending and east-west-trending lines. The data files have been processed using EdgeTech Discovery software and Chesapeake SonarWIZ, as follows. They were corrected for layback and tides and for the lateral offset between the ship GPS antenna and the towed fish. They were also adjusted vertically to fit the bathymetry data. Additionally, a basic swell filter was applied. The files are in standard SEG-Y format and the headers contain D-GPS-derived navigation information. The sub-bottom data was collected to reveal subsurface geometry and the thickness of sediment layers, and to guide subsequent sediment coring. The work was funded with CT DEEP award CDEP 2003-191.