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The Navigation Data Includes:
GPS navigation was fed to the acquisition system every second by the R/V G.K. Gilbert's onboard navigation system, a Trimble Nav Graphic receiver. The accuracy of this receiver is within 100 m, however the data proved to be of poor quality and required extensive editing. A filter was designed to remove spurious data values and these edited results were used to generate the trackline maps provided on this CD-ROM. These maps were generated with ArcView 3.2 as geographic projections, and are provided as GIF images. A position for every 500th shotpoint is also provided for easy registering of the data. All navigation files are stored as flat ASCII text files. The raw navigation files do not have the year or Julian day written into the record and are located in the RAWNAV subfolder of the NAV folder located at the top level of the CD-ROM. The edited navigation files have year and Julian day handwritten into each record and are stored in the EDITNAV subfolder of the NAV folder, and the 500 shotpoint interval files are stored in the SHOTNAV subfolder of the NAV folder. These files also have year and Julian day handwritten into each record.
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