HYPACK NAVIGATION: Text Files of the DGPS Navigation Logged with HYPACK Software on April 17, 2010 During U.S. Geological Survey Cruise 2010-010

Frequently-anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  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?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How should this data set be cited?

   U.S. Geological Survey, 2012, HYPACK NAVIGATION: Text Files of the DGPS Navigation Logged with HYPACK Software on April 17, 2010 During U.S. Geological Survey Cruise 2010-010: Open-File Report 2011-1149, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

   Online Links:

   • <https://pubs.usgs.gov/of/2011/1149/data/navigation/2010-010-Rafael/2010-010-Rafael.zip>
   • <https://pubs.usgs.gov/of/2011/1149/html/catalog.html>

   This is part of the following larger work.

   McMullen, K.Y., Poppe, L.J., Danforth, W.W., Blackwood, D.S., Shaer, J.D., Glomb, K.A., and Doran, E.F., 2012, Sea-Floor Geology of Long Island Sound North of Duck Pond Point, New York: Open-File Report 2011-1149, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

   Online Links:

   • <https://pubs.usgs.gov/of/2011/1149/>

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -72.636583

   East_Bounding_Coordinate: -72.412304

   North_Bounding_Coordinate: 41.149162

   South_Bounding_Coordinate: 41.109611

3. What does it look like?

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

   Calendar_Date: 17-Apr-2010

   Currentness_Reference: ground condition

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

   Geospatial_Data_Presentation_Form: text file

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.

      The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      

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. LongIsland09 should be LongIsland10
   
   ELL: Ellipsoid information. The name of the ellipsoid followed by the semi-major axis in meters and the flattening ration.
   PRO: Project information record where TME indicates Transverse Mercator and the central meridian of -75 indicates UTM, zone 18.
   DTM: Datum transformation record.
   GEO: Geoid Model File. Blank if not present. GEO <geo_file> <h_corr> where 'h_corr' is orthometric height correction in meters.
   HVU: Horizontal and Vertical Units (meters)
   TND: Survey time and date in UTC.
   DEV 0: Indicates that the lines with device designation 0 are lines of bathy data. ***Not present on this cruise.
   OFF 0: device offsets for device 0. Format of the value is OFF dn n1 n2 n3 n4 n5 n6 n7 where dn=device number; n1=starboard, port offsets where positive is starboard; n2=forward, aft offset where positive is forward; n3=height (antenna) or depth (transducer draft) offset - always positive; n4=yaw rotation angle where positive for clockwise rotation; n5=roll rotation angle where port side up is positive; n6=pitch rotation angle where bow up is positive; n7=device latency in seconds. No offset for device 0 during this data collection.
   DEV 1: Indicates that the lines with device designation 1 are lines of CSI LGBX Pro DGPS data.
   OFF 1: device offsets for device 1 - see description above (no offset for device 1 used during this data collection)
   USR: User of the software.
   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.
   POS: Position of the ship - in this case the antenna location - 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 18, WGS84.
   EC1: Echo Sounding (single frequency) in the format "EC1 dn t rd" where dn=device number; t=time tag (seconds past midnight); rd=raw depth.
   
   GYR: Gyro Data (heading) in the format "GYR dn t h" where dn=device number; t=time tag (seconds past midnight); h=ship heading angle.
   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. On this cruise, three different messages were sent from the DGPS: $GPVTG, $GPZDA, $SDDPT, and $GPGGA. These will be defined later.
   
   FIX: Event marked manually by the user in the format "FIX dn t event number where dn=device number; t=time tag (seconds past midnight); event number=event number (1,2,3...) automatically increments. The device number is automatically supplying a value of 99.
   The NMEA strings present in the HYPACK file are the $GPVTG, $GPZDA, $SDDPT, and $GPGGA. The $SDDPT only occurs in two files. These sentences are defined as follows.
   $GPVTG is track made good and ground speed in the format "$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.
   
   $GPGGA is GPS fix data in the format "$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.
   $SDDPT is water depth relative to the transducer, the depth offset of the transducer, and maximum depth that the sounder can detect a sea-bed (all in metres only). Positive offsets provide distance from the transducer to the water line. Negative offsets provide distance from the transducer to the keel.

   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)
   • U.S. Geological Survey

2. Who also contributed to the data set?

3. To whom should users address questions about the data?
   Katherine McMullen
   U.S. Geological Survey
   Field and Laboratory Technician
   384 Woods Hole Rd.
   Woods Hole, MA 02543-1598
   

   (508) 548-8700 x2277 (voice)
   (508) 457-2310 (FAX)
   kmcmullen@usgs.gov
   

Why was the data set created?

The purpose of these data is to provide the navigation for one day of USGS cruise 2010-010 as recorded by CSI LGBX Pro Differential Global Positioning System (DGPS) with HYPACK software. This provides an archive of the original navigation as well as allowing others to reprocess the navigation for their purposes.

How was the data set created?

1. From what previous works were the data drawn?

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

   Date: 2010 (process 1 of 1)

   A USB thumb drive was used to transfer the text navigation files from the computer running the HYPACK navigation software. The original HYPACK navigation files are stored in a single folder. The filenames are in the format of linenumber_starttime.julianday. An example filename is 000_1343.315 which reflects line 000, start time 1343 and Julian day 315. The times in the filename reflect UTC (Coordinate Universal Time) times.

   Person who carried out this activity:
   

   Larry Poppe
   U.S. Geological Survey
   Geologist
   384 Woods Hole Rd.
   Woods Hole, MA 02543-1598
   

   (508) 548-8700 x2314 (voice)
   (508) 457-2310 (FAX)
   lpoppe@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?

   The navigation receiver used was a CSI LGBX Pro DGPS2. The accuracy of this system is better than 10 meters.

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 version 10.0.5.31 during April 17, 2010 of USGS cruise 2010-010.

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

   These are the original files recorded by the HYPACK navigation software. No additional checks 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:

The 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 originator of the dataset.

1. Who distributes the data set? (Distributor 1 of 1)
   Larry Poppe
   U.S. Geological Survey
   Geologist
   384 Woods Hole Rd.
   Woods Hole, MA 02543-1598
   

   (508) 548-8700 x2314 (voice)
   (508) 457-2310 (FAX)
   lpoppe@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 the National Oceanic and Atmospheric Administration (NOAA), nor the Connecticut Department of Environmental Protection (CT DEP), 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, NOAA, or CT DEP 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?
   • Availability in digital form:

     Data format:	This WinZip file contains the ANSI text HYPACK navigation files as well as the associated metadata files. in format WinZip (version 9.0) Size: 1 MB
     Network links:	<https://pubs.usgs.gov/of/2011/1149/data/navigation/2010-010-Rafael/2010-010-Rafael.zip> <https://pubs.usgs.gov/of/2011/1149/html/catalog.html>
     Media you can order:	DVD-ROM (Density 4.75 Gbytes) (format UDF)

   • Cost to order the data: None.

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

   The user must have software capable of uncompressing the WinZip file.

Who wrote the metadata?

Dates:

Last modified: 16-May-2010

Metadata author:

Katherine McMullen
U.S. Geological Survey
Field and Laboratory Technician
384 Woods Hole Rd.
Woods Hole, MA 02543-1598

(508) 548-8700 x2277 (voice)
(508) 457-2310 (FAX)
kmcmullen@usgs.gov

Metadata standard:

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

Metadata extensions used:

• <http://www.esri.com/metadata/esriprof80.html>