USGS Home
Contact USGS
Search USGS

Navigation Data and Maps

Trackline Maps

Trackline maps were created with ESRI ArcGIS 9.1 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.

Location Map
Survey Area Map (Lines 06c01-06c08)

Processed Shotpoint Navigation

Shotpoint navigation files and 1,000-shot-interval location files were extracted from the trace headers of each line using Seismic UNIX software. These files were then processed with PROJ.4 software (http://www.remotesensing.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 offset between the shotpoint and GPS antenna (see fig. 1).

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 15)
Field 2: UTM Y (Zone 15)
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

Processed 1,000-Shot-Interval Location Navigation

Raw Shotpoint Navigation

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 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)