Open-File Report 03-497
NAVIGATION DATA AND MAPS
SEISMIC TRACKLINE MAPS
The trackline maps were generated with ESRI GIS software ArcView 3.2 and 8.1, exported to Adobe Illustrator for further editing, and saved in JPEG format. These JPEG images can be found in the MAPS folder. For details about the GIS project included on these discs, refer to the Software page.
Click on the links below to view the trackline maps.
NOTE: The location of missing navigation data is inferred by linear interpolation of the first and last known data points.
NOTE: If shotpoint locations are shown on the trackline map, then the trackline map may also be referred to as a shotpoint map.
EDITED SHOTPOINT NAVIGATION
ASCII navigation files were extracted from the SEG-Y headers using Seismic Unix software and edited to remove spurious data points and fix incorrectly recorded dates. The data were then processed using PROJ.4 software (http://www.remotesensing.org/proj) to convert latitude and longitude to Zone 15 UTMs and reformatted for use with ESRI's ArcView GIS software. Both sets of coordinates are provided for all lines.
Edited navigation files and 500-shot interval files can be accessed through the links provided below or from within the NAV folder. Edited shotpoint navigation files are located in the EDITNAV folder, and edited 500-shot interval files are located in the SHOTNAV folder. These files are all stored by cruise ID with a .txt extension. Each contains eight fields separated by commas and defined as follows:
RAW SHOTPOINT NAVIGATION
Raw navigation data can be found in the RAWNAV folder. The data are stored by Cruise ID and trackline number with a .txt extension. Each file contains six fields separated by a space and defined as follows:
WARNING: These data contain errors and have not been edited.
NOTE: The navigation data have not been corrected to reflect the 20-m offset between the shotpoint and the GPS antenna.