Skip past header information
 Link to USGS Home Page
Geophysical Surveys of Bear Lake, Utah-Idaho, September, 2002, OFR 03-150

Skip past index


Navigation for the cruise was acquired using the Wide Area Augmentation System (WAAS), a GPS-based navigation and landing system providing precision guidance to aircraft. The horizontal and vertical accuracies of WAAS are comparable to those of Differntial GPS. Due to the interior location of the study area, Coast Guard Becons providing differential corrections to GPS readings, were not accessible. Thus, WAAS was chosen as the navigation system.

Navigation files were created as follows: 'WAAS navigation' was generated by pulling the navigation fix and the depth, as recorded by the R/V Rafeal's hull-mounted echosounder, from the raw navigation files as recorded by Coastal Oceanographics, Inc. Hypack Max navigation acquistion package. The 2 - 4 second fixes were 'stripped' out of the raw navigation using various UNIX utilities. 'Sidescan-sonar navigation' was generated by pulling navigation from the sidescan-sonar headers. The navigation for individual tracklines was then combined using UNIX utilities. 'Shot navigation' was generated by stripping the navigation for each shot from the SEG-Y header and reformatting the data using various UNIX utilies. 'Shot navigation - 500 shot interval' was generated by extracting navigation for every 500 shots from the 'shot navigation' file. Navigation for the first shot of each line was extracted from the 'Shot navigation' file to generate the 'Start of line' file.

To view the trackline information see Figure 2, Figure 3, and Figure 5, or view navigation data within the ArcView project file stored on this CD-ROM. See GIS Data for more information.

WAAS Navigation
NOTE: Depth values of '99.990' represent eroneous depth measurements. Depth was not accurately measured along the steep, eastern side of the lake.
Sidescan-sonar Navigation
Shot Navigation
Shot Navigation - 500 shot interval
Start of Line

To view files in PDF format, download free copy of Adobe Acrobat Reader

Skip past footer information
Title Page / Contents / Project Description / GIS Data / Contacts

[an error occurred while processing this directive]