U.S. Geological Survey Data Series 348
Trackline maps were created with ESRI ArcGIS 9.2 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.
NOTE: Navigation errors, of unknow origin, occurred during data collection of lines 02b80 - 02b91; see Lake Ada Navigation Map below to view the affected tracklines and raw navigation fixes. The time interval between navigation fixes varies from 2 s to 1 min 30 s. The lines depicted on the Lake Ada trackline map were not modified during processing to remove any extraneous points associated with these errors.
Shotpoint navigation files and 500-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 latitude and longitude coordinates from UTM 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 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: Longitude (decimal degrees)
Field 2: Latitude (decimal degrees)
Field 3: Trackline Number
Field 4: Shotpoint Number
Field 5: UTM X (Zone 17)
Field 6: UTM Y (Zone 17)
Field 7: Year
Field 8: Day of Year:Hour:Minute:Second (UTC)
Processed Shotpoint Navigation (1.1-MB ASCII text file)
Processed 500-Shot-Interval Location Navigation (5.6-KB ASCII text file)
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 (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: UTM X (Zone 17)
Field 4: UTM Y (Zone 17)
Field 5: Year
Field 6: Day of Year:Hour:Minute:Second (UTC)