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U.S. Geological Survey Data Series 772
Navigation Data and MapsHome | Acronyms | Contents | Navigation | Profiles | Logs | Metadata | Software | Index
The trackline maps listed below represent the vessel position during the survey; the navigation data used to create these maps have not been corrected for the offset between the GPS antenna and the chirp's towfish (figure 2).  The trackline maps were created with ESRI ArcGIS 10 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 maps folder. For more information about the GIS project, refer to the Software page. 
Trackline Maps11BIM01 Location Map- 11BIM01 Area 1   Map 
- 11BIM01 Area 2   Map 
- 11BIM01 Area 3   Map 
- 11BIM01 Area 4   Map 
- 11BIM01 Area 5   Map 
- 11BIM01 Area 6   Map 
Processed Shotpoint Navigation
In addition to shotpoint navigation files, 1,000-shot-interval files were generated to help correlate shot locations on the map with evenly spaced 1,000-shot index markers along the top of the printable profile images. The 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 readlljsfnew script (located in chirpll.tar (43-KB PDF), which can be found in the su folder). Shotpoint coordinates were then projected from latitude and longitude coordinates to UTM northings and eastings (WGS84, Zone 16, meters) using PROJ.4 software (http://trac.osgeo.org/proj/) and reformatted for use with ESRI GIS software. A file containing the location of the start of each line was also created for use on the trackline maps. The processed navigation data have not been corrected for the offsets between the shotpoint and GPS antenna (fig. 2).

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 NumberField 4: Shotpoint NumberField 5: Longitude (decimal degrees)Field 6: Latitude (decimal degrees)Field 7: YearField 8: Day of Year:Hour:Minute:Second (UTC)

11bim01.txt - Processed Shotpoint Navigation (55-MB ASCII text file)

s11bim01.txt - Processed 1,000-Shot-Interval Location Navigation (53-KB ASCII text file)
Raw Shotpoint Navigation
Shotpoint navigation files, consisting of unique navigation fixes, 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 NumberField 2: Shotpoint NumberField 3: Longitude (decimal degrees)Field 4: Latitude (decimal degrees)Field 5: YearField 6: Day of Year:Hour:Minute:Second (UTC) 
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U.S. Department of the Interior | U.S. Geological SurveyURL: http://pubs.usgs.gov/ds/772/html/nav.htmlPage Contact Information: GS Pubs Web ContactPage Last Modified: Thursday, July 18, 2013, 12:17:39 PM