Near-bottom processed sidescan sonar Deep Tow mosaiced grids from the East Pacific Rise at 17°S and 19°S (1998)

This data set presents sidescan sonar grid mosaics. The sidescan sonar data set was collected using the Scripps Institution of Oceanography (SIO) deeply towed instrument package (Deep Tow) at 17°S and 19°S, East Pacific Rise, during cruise PANR06MV (May 1998, chief scientist Jeff Gee). The Deep Tow platform carried a 110 kHz sidescan sonar. The binary data files were originally recorded in SIO fish6 format, and were converted to the MB-System-compatible .mb71 format (mbio format 71) for processing. Processing steps included translating time-based sonar data into backscatter records, and laid out into a regular array of pixels that were projected onto a flat seafloor model (swath bathymetric data were not collected). Data were corrected for the variation of amplitude with grazing angle, filtered with a Gaussian mean low-pass filter (across track /along track dimensions of 11 and 3 pixels, respectively), and mosaiced. Processing was carried out with MB-System release 5.7.6, with mosaics for each profile, organized by day, provided as GMT-compatible netCDF grids. The file name letters ZSsCF mean that the time-based Sidescan sonar data were laid out into a regular array of pixels on the seafloor (i.e. depth, Z), mosaiCed, and Filtered. The data set was generated as part of the projects called Short Wavelength Magnetic Variations within the Central Anomaly on the Southern EPR, and Along-Axis Continuity of Oceanic Detachment Faults. Funding was provided through NSF awards OCE97-12027, OCE14-59387 and OCE18-39727.