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U.S. Geological Survey Data Series 238

Navigation Data and Maps


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Trackline Maps

Trackline maps were generated with ESRI ArcView 3.3 and ArcGIS 8.3 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 (see fig. 1). For more information about the GIS project, refer to the Software page.

The trackline maps on the following pages 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 by equipment type. For details about the interactive and printable profiles, see the Profiles page.

Table 3 lists the lines that appear on each of the chirp maps. The boomer map shows all boomer lines.

Boomer Map

Chirp Map
Chirp Area A Map
Chirp Area A1 Map
Chirp Area A2 Map
Chirp Area A3 Map
Chirp Area B Map


Processed Shotpoint Navigation

Shotpoint navigation files and 500- or 1,000-shot-interval location files were extracted from the trace headers of each line using Seismic Unix software. These files were then processed using PROJ.4 software (http://www.remotesensing.org/proj) to generate latitude and longitude from UTMs 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).

Processed navigation can be accessed through the links provided below or from within the NAV folder. Processed shotpoint navigation files are located in the PROCNAV folder. Processed boomer 500-shot-interval location files and chirp 1,000-shot-interval location files are located in the SHOTNAV 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 15)
Field 6: UTM Y (Zone 15)
Field 7: Year
Field 8: Day of Year:Hour:Minute:Second (UTC)

Processed Shotpoint Navigation
Boomer
Chirp

Processed 500- or 1,000-Shot-Interval Location Navigation
Boomer
Chirp


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 equipment type. 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 15)
Field 4: UTM Y (Zone 15)
Field 5: Year
Field 6: Day of Year:Hour:Minute:Second (UTC)


Home | Acronyms | Contents | Navigation | Profiles | Logs | Metadata | Software