|95LCA03 and 96LCA02 Data Archive|
Trackline maps were created with ESRI ArcGIS 9.0 software, exported to Adobe Illustrator for further editing, and saved in JPEG format. These images can be accessed through the links provided below or from within the CRUISENAV folder. The navigation data used to create these maps have not been corrected for the offset between the shotpoint and GPS antenna (see fig. 1). For more information about the GIS project, refer to the Software page.
The trackline maps contain links to interactive profiles, printable profiles, and line navigation maps. The line navigation maps, which have been corrected for the GPS offset, were created with CTI SonarWeb software and are stored in the LINENAV folder. Refer to the Profiles page for more information about the interactive and printable profiles.
Navigation is incomplete for several lines. On the trackline maps, the location of missing navigation data within a line is inferred by linear interpolation of the first and last known data points. A cross marks the location of the first available navigation fix for lines missing navigation at the start of line. A SonarWeb line navigation map is not available for 95LCA03 line PRSB_2 due to a lack of accurate navigation for that line.
Refer to table 3 for a list of which lines appear on each of the trackline maps.
Full Survey Area Map
Shotpoint navigation files and 500-shot-interval location files were extracted from the trace headers of each line using Seismic Unix software and edited to remove spurious data points and fix incorrectly recorded dates. These files were then processed with PROJ.4 software (http://www.remotesensing.org/proj) to generate UTMs from latitude and longitude and reformatted for use with ESRI GIS software. The edited navigation data have not been corrected for the offset between the shotpoint and GPS antenna (see fig. 1).
The edited shotpoint navigation and 500-shot-interval location files can be accessed through the links provided below or from within the NAV folder. Each ASCII text file contains eight fields separated by commas and defined as follows:
Field 1: UTM X (Zone 17)
Field 2: UTM Y (Zone 17)
Field 3: Trackline Number
Field 4: Shotpoint Number
Field 5: Longitude (decimal degrees)
Field 6: Latitude (decimal degrees)
Field 7: Year
Field 8: Day of Year:Hour:Minute:Second (UTC)
Edited Shotpoint Navigation
Edited 500-Shot-Interval Location Navigation
Shotpoint navigation files were extracted from the trace headers of each line using Seismic Unix software. Unedited navigation files are stored as ASCII text files in the RAWNAV folder by field activity ID. These navigation data have not been corrected for the offset between the shotpoint and GPS antenna (see fig. 1). Each file contains six fields separated by a space and defined as follows:
Field 1: Trackline Number
Field 2: Shotpoint Number
Field 3: Longitude (decimal degrees)
Field 4: Latitude (decimal degrees)
Field 5: Year
Field 6: Day of Year:Hour:Minute:Second (UTC)
WARNING: These data contain errors and have not been edited.