USGS - science for a changing world

U.S. Geological Survey Data Series 653

Navigation Data and Maps


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


Trackline Maps

A trackline map was created with ESRI GIS software ArcView 3.3 and ArcGIS 8.3, exported to Adobe Illustrator for further editing, and saved in JPEG format. This image can be accessed through the link provided below or from within the maps folder. For more information about the GIS project, refer to the Software page.

NOTE: No digital data were collected for trackline 02b42. Navigation is intermittent for several lines. On the trackline map, the location of missing navigation data within a line is inferred by linear interpolation of the first and last known data points, and large gaps of 700 shots or more are represented by a dashed yellow line.

Click here to view the trackline map.


Processed Shotpoint Navigation

In addition to shotpoint navigation files, 500-shot-interval files were generated to help locate shot locations on the map with features identified on the profiles. Both 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://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 to reflect the approximately 30-m offset between the shotpoint and GPS antenna (figure 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 are 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 17N)
Field 6: UTM-Y (Zone 17N)
Field 7: Year
Field 8: Day of Year:Hour:Minute:Second (GMT)

Processed Shotpoint Navigation (11.7-KB ASCII text file)
Processed 500-Shot-Interval Location Navigation (53-KB ASCII text file)


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 trackline number. These navigation data have not been corrected to reflect the approximately 30-m offset between the shotpoint and GPS antenna. Each file contains six fields separated by a space and are defined as follows:

Field 1: Trackline Number
Field 2: Shotpoint Number
Field 3: UTM-X (Zone 17N)
Field 4: UTM-Y (Zone 17N)
Field 5: Year
Field 6: Day of Year:Hour:Minute:Second (GMT)

NOTE: These data contain errors and have not been edited.


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

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: https://pubs.usgs.gov/ds/653/html/nav.html
Page Contact Information: Contact USGS
Page Last Modified: Monday, November 28, 2016, 06:55:55 PM