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NAVIGATION DATA

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RAW DGPS SHOTPOINT NAVIGATION

The unedited differential GPS (DGPS) navigation files for each field activity were collected using a USGS DGPS system (WAAS/Beacon receiver coupled with Hy-Pack navigation software). Delph Seismic acquisition software was used to extract these shotpoint files from the undefined fields in the SEG-Y seismic trace headers for each unique fix available (about every 1 second).

The raw data for each field activity can be accessed using the field activity ID links provided below. It can also be found in the field activity ID subfolders located within the RAWNAV subfolder of the NAV folder located at the top level of these CD-ROMs. The data is stored in flat ASCII text file format by trackline number and with a .txt extension. Each file contains six fields separated by a space. Each of these fields is defined as follows:

RAW NAVIGATION DATA: 01ASR01 | 01ASR02 | 02ASR01 | 02ASR02

WARNING: This data has not been checked for errors.

NOTE: The shotpoint navigation provided in this report has not been corrected to reflect the 5 meter offset of the shotpoint to the GPS antenna.


EDITED SHOTPOINT NAVIGATION

The edited shotpoint navigation files were extracted from the SEG-Y seismic trace headers using Seismic Unix software. They were then processed using PROJ.4 (UNIX/LINUX shareware currently located at http://remotesensing.org/proj) to convert the UTM coordinates to latitude and longitude.

The edited navigation files for each field activity can be accessed using the field activity ID links provided below. These files can also be found by field activity ID within the EDITNAV subfolder of the NAV folder located at the top level of these CD-ROMs. The data is stored as flat ASCII text files by field activity ID and with a .txt extension. 500-shot interval files for each field activity have also been included. These files are also stored as flat ASCII text files by field activity ID and with a .txt extension. They can be accessed through the field activity ID links provided below or from within the SHOTNAV subfolder of the NAV folder. The shotpoint navigation files and the 500-shot interval files both contain eight fields separated by commas. Each of these fields is defined as follows:

EDITED SHOTPOINT NAVIGATION: 01ASR01 | 01ASR02 | 02ASR01 | 02ASR02

500-SHOT INTERVAL NAVIGATION: 01ASR01 | 01ASR02 | 02ASR01 | 02ASR02


SEISMIC SHOTPOINT MAPS

Note: the web version of this archive does not contain GIS files. To obtain a complete copy of this archive, contact USGS Information at (888) ASK-USGS.

The edited shotpoint navigation files and 500-shot interval files were used to generate shotpoint maps with ESRI's GIS software ArcView 3.2. The maps were then exported to Adobe Illustrator for final editing and conversion to GIF images. These GIF images can be found in the MAPS folder located at the top level of these CD-ROMs. The ArcView project and all associated shapefiles used in the creation of the maps can be found in the ARC subfolder of the SOFTWARE folder located at the top level of Disc 2. They can be viewed using ESRI's ArcView and ArcGIS software or ArcExplorer shareware, currently located at http://www.esri.com/software/arcexplorer.

Click on the following links to see the seismic shotpoint maps and to access the seismic image files:


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