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Navigation Data and Maps

Trackline Maps

Trackline maps were created with ESRI ArcGIS 9.3 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 (figs. 1A and 1B). For more information about the GIS project, refer to the Software page.

The trackline maps contain links to the geospatially interactive profiles; the geospatial profile pages contain links to the 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 geospatial and printable profiles.

Location Map

• Area 1
• Area 1A
• Area 1B
• Area 1c
• Area 1d
• Area 2

Processed Shotpoint Navigation

In addition to shotpoint navigation files, 1,000-shot-interval files were generated to help locate shot locations on the map with features identified on the profiles. Both shotpoint navigation files and 1,000-shot-interval location files were extracted from the trace headers of each line using Seismic Unix software via the readll_chirp script (located in chirp.tar, which can be found in the su folder). These files were then processed with PROJ.4 software (http://trac.osgeo.org/proj/) to generate UTM coordinates from latitude and longitude coordinates and reformatted for use with ESRI GIS software. The processed navigation data have not been corrected for the offsets between the shotpoint and GPS antenna (figs. 1A and 1B).

The processed shotpoint navigation and 1,000-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 16)
Field 2: UTM Y (Zone 16)
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)

Processed Shotpoint Navigation
09cct03 (41.2 MB ASCII text file)
09cct03a (18.9 MB ASCII text file)
09cct04 (25.5 MB ASCII text file)

Processed 1,000-Shot-Interval Location Navigation
s09cct03 (38.1 KB ASCII text file)
s09cct03a (17.4 KB ASCII text file)
s09cct04 (24.3 KB ASCII text file)

Raw Shotpoint Navigation

Raw shotpoint navigation files were extracted from the trace headers of each line using Seismic Unix software. Unprocessed navigation files are stored as ASCII text files in the rawnav folder by trackline number. These navigation data have not been corrected for the offset between the shotpoint and GPS antenna. 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)