Bo´sun, a high resolution automatic charting system for the continental shelf

BO´SUN comprises hardware and software for generating, recording, and processing high resolution sonar data to produce contoured depth charts in depths to 2,000 feet. The hardware includes a multibeam acoustic depth sounder, CRT display, digital printer, and digital magnetic tape recorder which logs both sonar and navigation data. The software permits shore processing of the magnetic tape on a conventional general purpose computer and digital plotter to develop annotated contour charts with selectable scale and contour interval. The 21 beam version of BO´SUN has a lateral sweep of 105 and logs 11 soundings on each transmission. The magnetic tape records the sonar slant range, time, roll, heading, and navigation range-range coordinates. The software computes exact position and depth for each sounding, correcting for sound velocity, refraction, roll, tide, compass deviation, ship´s coordinates and location of transducer relative to ship´s navigation center. There is provision for editing, averaging, interpolating, and smoothing. Survey runs of any geometry including overlapping swaths are han-died by sort and merge routines which collect all data available at each grid point. A sophisticated navigation editor has been developed to cope with erratic electromagnetic propagation. A plot of ship´s track can be run before and after editing.