--------------------------------------------------------------------------- ARCHIVE OF THE ISIS SIDESCAN SONAR AND DGPS NAVIGATION FIELD DATA COLLECTED ON USGS CRUISE 95009, 1 - 14 August, 1995 U.S. Geological Survey Open-File Report 97- 473 by Brynn L. Bemis1 Dr. William C. Schwab2 Valerie F. Paskevich2 1Wesleyan University, Dept. of Geology,Middletown, CT 06459 2U.S. Geological Survey, Woods Hole Field Center, Woods Hole, MA 02543 --------------------------------------------------------------------------- INTRODUCTION This CD-ROM (Compact Disc-Read Only Memory) has been produced in accordance with the ISO 9660 CD-ROM Standard and is therefore capable of being read on any computing platform that has appropriate CD-ROM driver software installed. Access to the data and information contained on this CD-ROM was developed using the HyperText Markup Language (HTML) utilized by the World Wide Web (WWW) project. Development of the CD-ROM documentation and user interface in HTML allows a user to access the information by using a variety of WWW information browsers (i.e. NCSA Mosaic, Netscape) to facilitate browsing and locating information and data. To access the information contained on this disk with a WWW client browser, open the file 'index.htm' at the top level directory of this CD-ROM with your selected browser. The HTML documentation is written utilizing some HTML 3.0 enhancements. The disk should be viewable by all WWW browsers but may not properly format on some older WWW browsers. Also, some links to USGS collaborators and other agencies are available on this CD-ROM. These links are only accessible if access to the Internet is available during browsing of the CD-ROM. The archived sidescan data may be downloaded and processed. There is software available on this CD-ROM for viewing the individual swath using any computer system running the UNIX operation system. See the "readme" file in the BIN directory for details. --------------------------------------------------------------------------- BACKGROUND This CD-ROM contains copies of the navigation and field sidescan sonar data collected during USGS Cruise 95009, conducted during 1-14 August, 1995. The cruise was conducted as part of a collaborative field program between researchers at Coastal Carolina University and the USGS, Marine and Coastal Geology Program, Woods Hole Field Center. During the first line of the first day of survey (JD 216), the seas were too rough to yield good records. However, we decided to run the line and see the maximum range of data expected for this area. Day 2 (JD 220) proceeded smoothly, but due to bad weather we headed into port for the evening. On Day 3 (221:15:35 through 221:16:02) we lost DGPS and ran on GPS. At the end of Day 4 (JD 222) we again returned to the dock. During Days 5,6,7 (JD 223,224,225) we experienced no problems. --------------------------------------------------------------------------- This CD-ROM contains six main directories: Directory DATA: Contains the raw sidescan data. These data were collected using a Klein 100-kHz sidescan sonar system and were logged on a Triton Technologies, Inc., ISIS system. The sidescan sonar data were collected at a resolution of 100 m per side. The sidescan data are 8-bit binary, and the format is summarized in a text file located in the DOC directory. The data description is also available in HTML format. The archived sidescan data is split and stored on 11 separate disks. Go to the Field Data from the main page to access the data. Directory DOC: Contains ASCII documentation on the sidescan sonar data file formats collected using the ISIS system. This directory also contains ASCII copies of the cruise report and a description of the navigation data files contained in the NAV directory. Directory NAV: Contains the navigation that were collected during the sidescan component of the field program using a USGS differential GPS system manufactured by Ashtech. The USGS GPS shorebased station broadcast differential corrections to the ship and utilized USGS benchmark CJ-1384 for vertical and horizontal control. WARNING: This data has not been checked for errors. Use with caution. NAV sub-directory: The files in this directory have been reformatted from the original raw navigation data file using the UNIX awk utility (the awk script file is located in the SCRIPTS sub-directory) to allow for easier viewing . Every navigation fix from the original raw data has been preserved. The navigation is stored in ASCII files with six fields separated by tabs. Each file represents a separate cruise day (i.e. jd177.txt). Navigaton fixes are at 10 second intervals. The start and end of each line is marked within each file. Field 1: date and time (julian day:hour (GMT):minute:second) Field 2: Latitude (ie. 32d.59375 ) Field 3: Longitude (ie. -79d.968975) Field 4: Speed (computed from the navigation) Field 5: Heading (computed from the navigation) Field 6: Water Depth (derived from an Odem digital echo sounder). ** Depths are in meters, but have not been corrected for the depth of the transducer, which was about 2 m below the sea surface, nor for the tide. (for tidal information and 6 minute tidal data, see http://www.olld.nos.noaa.gov/data_res.html) RAWNAV sub-directory: The raw USGS differential GPS data is located in this directory. These files (i.e. jd177) represent the data as it was originally recorded on floppy disk aboard ship. The data are in NEMA format and contain the $GPGGA string. SCRIPTS sub-directory: Contains an awk script file used to reformat the raw navigation into a format more suitable for on-screen viewing or printing. See the readme.txt file in this sub-directory for details. Directory HTMLDOCS: Contains the necessary HTML files and supporting graphics to allow the user access to the CD-ROM via any World Wide Web (WWW) browser. Directory PLOTS: Contains two subdirectories containing postcript plots and images of the navigation. POSTSCRI sub-directory: Contains the navigation plots in PostScript format. GIFS sub-directory: Contains the navigation plots in Compuserve GIF format. Directory BIN: Contains the ShowImage program to view the raw data files on screen. The program only runs on systems that employ the UNIX operating system. Included are three separate sub-directories which contain the executable for the appropriate operating system: sgi, digunix, linux. See the readme.txt file in this directory for details. Directory IMAGES: Contains GIF and TIFF images that are used by HTML hyperlinks. --------------------------------------------------------------------------- DISCLAIMER This Compact Disc-Read Only Memory (CD-ROM) publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data published on this CD-ROM have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data, software, or related materials. --------------------------------------------------------------------------- [Image] Return to USGS Cruise 95009 home page.