Archive of Sidescan-Sonar Data
and DGPS Navigation Data
Collected During USGS Cruise SEAX 96004
New York Bight, 1 May - 9 June 1996
U.S. Geological Survey Open-File Report 01-95
by Jenna C. Hill, William C. Schwab and William W. Danforth
U.S. Geological Survey, Woods Hole Field Center, Woods Hole, MA 02543
This DVD-ROM (Digital Versatile Disc-Read Only Memory) has been produced in accordance
with the UDF (Universal Disc Format) DVD-ROM Standard and is therefore capable
of being read on any computing platform that has appropriate DVD-ROM driver software
Access to the data and information contained on this DVD-ROM was developed using
the HyperText Markup Language (HTML) utilized by the World Wide Web (WWW). Development
of the DVD-ROM documentation and user interface in HTML allows a user to access
the information by using a variety of WWW information browsers (i.e. Microsoft
Internet Explorer, Netscape) to facilitate browsing and locating information and
data. To access the information contained on this disc with a WWW client browser,
open the file 'index.htm' at the top level directory of this DVD-ROM with your
selected browser. The HTML documentation is written utilizing some HTML 4.0 enhancements.
The disc 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 DVD-ROM. These links are only accessible if access to the Internet is
available during browsing of the DVD-ROM.
The archived sidescan-sonar data may be downloaded and processed.
Software is available on this DVD-ROM for viewing an individual swath using any
computer running the UNIX operating system (Danforth,
1997). See the "readme" file in the
BIN directory for details.
Beginning in 1995, the USGS, in cooperation with the U.S Army Corps of Engineers
(USACE), New York District, began a program to generate reconnaissance maps of
the sea-floor offshore of the New York-New Jersey metropolitan area, one of the
most populated coastal regions of the United States. The goal of this mapping
program is to provide a regional synthesis of the sea-floor environment, including
a description of sedimentary environments, sediment texture, seafloor morphology,
and geologic history to aid in understanding the impacts of anthropogenic activities,
such as ocean dumping. This mapping effort differs from previous studies of this
area by obtaining digital, sidescan sonar images that cover 100 percent of the
This investigation was motivated by the need to develop an environmentally acceptable
solution for the disposal of dredged material from the New York - New Jersey Port,
by the need to identify potential sources of sand for renourishment of the southern
shore of Long Island, and by the opportunity to develop a better understanding
of the transport and long-term fate of contaminants by investigations of the present
distribution of materials discharged into the New York Bight over the last 100+
years (Schwab and others, 1997). Data collected in 1996, USGS cruise SEAX 96004,
augments data collected in 1995 with sidescan sonar and seismic reflection data
collected within the New York Bight Apex region. This report is an archive of
the sidescan-sonar data and DGPS navigation data collected in 1996.
Directory DATA: The DATA Directory contains
the raw sidescan-sonar data. These data were collected using a Datasonics100-kHz
sidescan-sonar system and were logged on a Triton-Elics Internation, Inc., ISIS
acquisition system. The sidescan-sonar data were collected at a range of 187.5
meters per side; 375 meter swath. The sidescan-sonar data are 16-bit binary; 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-sonar data are stored on 12 separate DVD-ROMs.
The Field Data can be accessed from the main page.
Directory DOC: The DOC Directory contains
ASCII documentation on the sidescan-sonar data file format 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: The NAV Directory contains
the navigation data that were collected during the sidescan-sonar component of
the field program, using a USGS differential GPS system manufactured by Ashtech.
Differential corrections were obtained from shore-based U.S. Coast Guard beacons.
These data have not been checked for errors. Use with caution.
Directory HTMLDOCS: The HTMLDOCS Directory
contains the necessary HTML files to allow the user access to the DVD-ROM via
any World Wide Web (WWW) browser.
The files in this directory have been reformatted from the original raw navigation
data file using the UNIX awk utility to allow for easier viewing. The awk file
is located in the SCRIPTS sub-directory. The script,
'rformnav.awk', is an awk script written to reformat raw navigation data (from
the "nav/rawnav directory) into six separate columns. The columns include:
date/time, latitude, longitude, speed of vessel, heading, and depth (meters).
The "awk" or "nawk" (new awk) command is available on any
system employing the UNIX operating system.
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. jd124web.txt represents Julian Day 124). Navigation
fixes are at ~10 second intervals.
- Field 1: Date and Time (julian day:hour (UTC):minute:second)
- Field 2: Latitude (ie. 32d59375 )
- Field 3: Longitude (ie. -79d968975)
- Field 4: Speed (computed from the navigation)
- Field 5: Heading (computed from the navigation)
- Field 6: Water Depth (derived from an Odem 3.5 kHz sub-bottom profiler).
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,
The raw USGS differential GPS data is located in this directory. These files
(i.e. jd128) represent the data as originally recorded on floppy disk aboard ship.
The data are in NEMA format and contain the $GPGGA string.
SCRIPTS sub-directory: The SCRIPTS sub-directory contains the awk script
file used to reformat the raw navigation into a format more suitable for on-screen
viewing and printing. See the readme.txt file in this sub-directory for details.
Directory BIN: The BIN Directory contains
the ShowImage program to view the raw data files on screen (Danforth,
1997). The program only runs on systems using the UNIX operating system. Included
are three separate sub-directories containing the executable for the appropriate
operating system: sgi, digunix, linux. See the readme.txt or readme.htm
files in the BIN directory for details.
The PDF sub-directory contains the Adobe Portable Document Format (PDF) navigation
plots. These files require Adobe Acrobat Reader for viewing (available free
The JPG sub-directory contains the navigation plots in JPEG format.
Directory IMAGES: The IMAGES Directory contains
GIF and JPEG images that are used by HTML hyperlinks.
Danforth, W.W., 1997, Xsonar/ShowImage: A Complete
System for Rapid Sidescan-Sonar Processing and Display, U.S. Geological Survey
Open-File Report 97-686, pp 1 - 79.
Schwab, W.C., Thieler, E.R., Denny, J.F., Danforth,
W.W. 2000. Seafloor Sediment Distribution Off Southern Long Island, New York:
U.S. Geological Survey Open-File Report 00-243, 3 Sheets.
This Digital Versatile Disc-Read Only Memory (DVD-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 DVD-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.
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