Text files of the navigation logged with HYPACK Software during survey 2012-005-FA conducted in Baltimore, Washington, and Norfolk Canyons by the U.S. Geological Survey in 2012.

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently-anticipated questions:


What does this data set describe?

Title:
Text files of the navigation logged with HYPACK Software during survey 2012-005-FA conducted in Baltimore, Washington, and Norfolk Canyons by the U.S. Geological Survey in 2012.
Abstract:
A large number of high-resolution geophysical surveys between Cape Hatteras and Georges Bank have been conducted by federal, state, and academic institutions since the turn of the century. A major goal of these surveys is providing a continuous view of bathymetry and shallow stratigraphy at the shelf edge in order to assess levels of geological activity during the current sea level highstand. In 2012, chirp seismic-reflection data was collected by the U.S. Geologial Survey aboard the motor vessel Tiki XIV near three United States mid-Atlantic margin submarine canyons. These data can be used to further our understanding of passive continental margin processes during the Holocene, as well as providing valuable information regarding potential submarine geohazards. For more information on the U.S. Geological Survey involvement in this effort, see <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2012-005-FA>.
  1. How should this data set be cited?

    U.S. Geological Survey, 2014, Text files of the navigation logged with HYPACK Software during survey 2012-005-FA conducted in Baltimore, Washington, and Norfolk Canyons by the U.S. Geological Survey in 2012.: Open-File Report 2014-1118, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Obelcz, Jeffrey, Brothers, Daniel S. , Uri S. ten Brink, Chaytor, Jason D. , Worley, Charles R. , and Moore, Eric M. , 2014, Chirp Seismic-Reflection Data From the Baltimore, Washington, and Norfolk Canyons, U.S. Mid-Atlantic Margin: Open-File Report 2014-1118, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -74.818581
    East_Bounding_Coordinate: -73.719947
    North_Bounding_Coordinate: 38.326116
    South_Bounding_Coordinate: 37.003238

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 23-May-2012
    Beginning_Time: 1011
    Ending_Date: 27-May-2012
    Ending_Time: 2355
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Point data set.

    2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees.

  7. How does the data set describe geographic features?

    Entity_and_Attribute_Overview:
    The times recorded in the navigation file are in UTC. Keywords and the information they provide are as follows:
    
    
    FTP: The first record located at the top of the header used to identify the file format.
    
    
    VER: HYPACK version number
    
    
    INF: General survey information filled in by the data technician. This typically contains the survey participants, the vessel name, other agencies involved with the survey, and the location of the survey.
    
    
    FIL: Raw format file.
    
    
    ELL: Ellipsoid information. The name of the ellipsoid followed by the semi-major axis in meters and the flattening ration.
    
    
    PRO: Projection information record where TME indicates Transverse Mercator and the central meridian of -75 indicates UTM, zone 18.
    
    
    DTM: Datum transformation record
    
    
    GEO: Geoid model. Blank if not present.
    
    
    HVU: Horizontal and Vertical Units (meters)
    
    
    TND: Survey time and date in UTC.
    
    
    OFF: Device Offsets in the format "OFF dn n1 n2 n3 n4 n5 n6 n7" where dn = device number; n1 = starboard or port offset (positive starboard); n2 = forward or aft offset (positive forward); n3 = height (antenna) or depth (transducer draft) offset; n4 = yaw rotation angle (positive for clockwise rotation); n5 = roll rotation angle (port side up is positive); n6 = pitch rotation angle (bow up is positive); n7 = device latency in seconds.
    
    
    DEV 0: Indicates navigation recorded from a Differential GPS nav system.
    
    
    DEV 1: This is the 512i chirp system depth/pressure sensor output passed to HYPACK. The units of the measurements are PSI.
    
    
    DDT: Unknown String (This appears in the HYPACK manual (v. 12.0.8.12) for Device Driver setup under YSI_6600.dll but there is no further explanation. It seems like some kind of place holder for a custom device driver of a "SMI" (Special Marine Instrument)).
    
    
    LIN 2: planned line data follows
    
    
    PTS: planned line waypoints (easting and northing, UTM, zone 18N, meters)
    
    
    LBP: planned line begin point (easting and northing, UTM zone 18N, meters)
    
    
    LNN: planned line name
    
    
    EOL: end of planned line
    
    
    USR: user information
    
    
    EOH: end of header.
    
    
    The remaining elements have similar information in the first 3 columns. The first column will indicate the data type, the second column will indicate the device that recorded the information and the third column is the time tag (seconds past midnight) that is also sometimes referred to as the latency. The remaining information on each line is specific to the data type. Not all data types were recorded in each HYPACK file.
    
    
    POS: Position of the ship in the format "POS dn t x y" where dn=device number; t=time tag (seconds past midnight); x=easting; y=northing. On this cruise these values are in UTM, Zone 19, WGS84.
    
    
    QUA: Position quality information in the format "QUA dn t n m h sat mode" where dn=device number; t=time tag (seconds past midnight); n=number of values to follow; m = 10 minus HDOP (horizontal dilution of precision); h=HDOP; sat=number of satellites; mode=GPS mode (NMEA 0183 standard values) where 0 = fix not available or invalid; 1 = GPS fix; 2 = Differential GPS fix; 3 = GPS PPS Mode fix; 4 = RTK fix; and 5 = RTK Float. The last 3 values are decoded from GST message: standard deviation of latitude error (meters); standard deviation of longitude error (meters); Standard deviation of semi-major axis of error ellipsis (meters).
    
    
    RAW: Position information in the format "RAW dn t n lat long alt utc" where dn=device number; t=time tag (seconds past midnight); n=number of values to follow; lat=raw latitude in the format ddmmmm.mmmm. To convert to ddmm.mmmmm multiply by 100; long=raw longitude in the format ddmmmm.mmmm. To convert to ddmm.mmmmm multiply by 100; alt=antenna altitude above ellipsoid (meters); utc=GPS time in the format HHMM.
    
    
    CAP: Information captured by the HYPACK system sent from an external device in the format "CAP dn t val" where dn=device number; t=time tag (seconds past midnight); val=value passed by the instrument. In this case the value being passed is a pressure depth value in the units of PSI. For example: *000126.9844 = 26.9844 PSI (disregard the *0001). One would need to subtract atmospheric pressure (1 atm ~= 14.7 psi_ from this value to obtain the sensor PSI reading.
    
    
    MSG: Message string in the format "MSG dn t message" where dn=device number; t=time tag (seconds past midnight); message is the message sent from the device. During survey 2012-005-FA there were several different messages were sent from the GPS systems: $GPGGA, $GPVTG, $GPRMC, and $GPZDA were standard throughout the survey. These message strings will be defined below.
    
    
    GYR: Gyro data (heading) in the format "GYR dn t h" where dn=device number, t=time tag (seconds past midnight), h=heading.
    
    
    FIX: events marked manually by the user in the format "FIX dn t event_number" where dn=device number (typically 99 as there is no device for manual events); t=time tag (seconds past midnight); event_number=event number such as 1,2,3,4.
    
    
    MSG strings from GPS:
    
    
    $GPGGA is GPS fix data in the format "$GPGGA, t, lat, lath, long, longh, q, sat, h, a, M, alt, M, t2, refcheck" where t=time in UTC in the format hhmmss.ss; lat=latitude in the format ddmm.mmmmmm; lath= N or S indicating the latitude hemisphere; long=longitude in the format dddmm.mmmmmm; longh=E or W indicating the longitude hemisphere; q=fix quality where 2 is a DGPS fix; sat=number of satellites; h=Horizontal Dilution of Precision (HDOP); a=Antenna altitude above mean sea level (geoid); M= units of antenna altitude in meters; alt=height of geoid above WGS84 ellipsoid; M=units of geoidal height in meters; t2=time since last DGPS update; refcheck=DGPS reference station id and the checksum.
    
    
    $GPRMC is the recommended minimum specific GPS/TRANSIT data in the format "$GPRMC, hhmmss.ss, A, llll.ll, a, yyyyy.yy, a,x.x, x.x, ddmmyy, x.x, a, m*hh" where hhmmss.ss=UTC time fix, A=data staus (A=valid position, V=navigation receiver warning), llll.ll=latitude in the format ddmm.mmm, a=North/South, yyyyy.yy=longitude in the format dddmm.mmm, a=East/West, x.x=speed over ground in knots, x.x=track angle in degrees true, ddmmyy=UTC date of fix, x.x=magnetic variation degrees (Easterly variation subtracts from true course), a= E or W of magnetic varation, m= mode indicate (A=autonomous, D=Differential, E=Estimate, N=Data not valid), *hh=checksum.
    
    
    $GPVTG is track made good and ground speed in the format "$GPVTG, t, T, m, M, n, N, k, K refcheck" where t=true course made good over ground, degrees; T indicates the previous number refers to true course; m=magnetic course made good over ground, dgrees; M indicates the previous number refers to magnetic course; n=ground speed; N indicates the previous number refers to Knots, k=ground speed; K indicates the previous number refers to Kilometers per hour, refcheck= checksum at the end of the string with the first character an *.
    
    
    $GPZDA is UTC Date/Time and local time zone offset in the format "$GPZDA, hhmmss.ss,dd,mm,yyyy, xx, yy checksum" where hhmmss.ss= time in UTC; dd=UTC day; mm=UTC month; yyyy=UTC year; xx=offset to local time zone in hours; yy=offset to local time zone in minutes;checksum ***on this cruise the navigation computer was set to UTC time so the $GPZDA string indicates zero time offset.
    Entity_and_Attribute_Detail_Citation:
    The definitions of the HYPACK strings were acquired from the HYPACK software manual available from: <http://www.hypack.com/>. The definitions of the NMEA strings were obtained from: <http://home.mira.net/~gnb/gps/nmea.html> and <http://www.actisense.com/Downloads/TechTalk/NMEA%200183/The%20NMEA%200183%20Information%20Sheet.pdf>.


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    Jeffrey Obelcz
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x. 2245 (voice)
    508-457-2310 (FAX)
    jobelcz@usgs.gov


Why was the data set created?

To provide all of the navigation data files acquired during USGS survey 2012-005-FA in Baltimore, Washington, and Norfolk Canyons. This survey was conducted aboard the M/V Tiki XIV. HYPACK software was used to log these navigation data.


How was the data set created?

  1. From what previous works were the data drawn?

    (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, raw HYPACK data.

    Type_of_Source_Media: disc
    Source_Contribution:
    Raw navigation data were saved in HYPACK format (<http://www.hypack.com>). File name convention is LLL_TTTT.DDD, where LLL is the HYPACK line number, TTTT is the 24 hour time for the beginning of the file, and DDD is the Julian day (JD). Times were recorded in UTC (Coordinate Universal Time).

  2. How were the data generated, processed, and modified?

    Date: 2012 (process 1 of 1)
    Raw HYPACK (ver. 12.0.8.12) navigation files were transferred from the navigation acquisition computer to a centralized data server on the survey vessel for accessibility and archival.
    The raw HYPACK navigation files are stored in separate directories indicating the acquisition Julian Day. The filenames in each folder are usually in the format of linenumber_starttime.julianday. For example, a filename of 284_1816.151 would represent planned survey HYPACK line number 284, start time 1816 and Julian Day 151. Times are recorded in UTC (Coordinate Universal Time). For the majority of the survey, the HYPACK line names do not match the sequential numbering of the seismic lines, so the ship's log should be consulted when determining the relationship between a given HYPACK file and a seismic line.

    Person who carried out this activity:

    Jeffrey Obelcz
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x. 2245 (voice)
    jobelcz@usgs.gov

  3. What similar or related data should the user be aware of?


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

  2. How accurate are the geographic locations?

    Differential GPS (DGPS) data were collected during this survey using a Hemisphere receiver. These data were typically incorporated into the geophysical data during acquisition and logged to these HYPACK files in the event that post-processing the horizontal positional information was necessary. The DGPS positional accuracy is estimated to be within 20 m. No instrument layback was accounted for.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    These files represent all the navigation recorded by the HYPACK software during USGS survey 2012-005-FA (which may also be referred to in the old field activity number style as 12005). This is the raw navigation data for survey data that was released in USGS Open-File Report (number placeholder) from Baltimore, Washington, and Norfolk Canyons. These data correspond with seismic data, but there appears to be a gap in the HYPACK navigation files on Julian day 144, 02:54 to 03:30.

  5. How consistent are the relationships among the observations, including topology?

    These are the original files recorded by the HYPACK navigation software. These data were checked but no modifications or corrections have been made to these files.


How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: none
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the source of this information.

  1. Who distributes the data set? (Distributor 1 of 1)

    Jeffrey Obelcz
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x. 2245 (voice)
    jobelcz@usgs.gov

  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

  4. How can I download or order the data?

  5. What hardware or software do I need in order to use the data set?

    These data are available as ASCII text files. To utilize these data, the user must have software capable of viewing text files and parsing the HYPACK navigation strings.


Who wrote the metadata?

Dates:
Last modified: 14-May-2013
Metadata author:
Jeffrey Obelcz
U.S. Geological Survey
Geologist
384 Woods Hole Road
Woods Hole, MA 02543-1598
USA

508-548-8700 x. 2245 (voice)
508-457-2310 (FAX)
jobelcz@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)


Generated by mp version 2.9.6 on Tue Jun 24 09:53:21 2014