Bratton, John F. , and Cross, VeeAnn A. , 2014, Raw HYPACK navigation logged during U.S. Geological Survey Field Activity 2010-006-FA in Indian River Bay, Delaware, in April 2010: Open-File Report 2011-1039, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.This is part of the following larger work.Online Links:
- <http://pubs.usgs.gov/of/2011/1039/data/navigation/hypack/hypacknav_raw.zip>
- <http://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html>
Cross, V.A., Bratton, J.F., Michael, H.A., Kroeger, K.D., Green, A., and Bergeron, E., 2014, Continuous Resistivity Profiling and Seismic-Reflection Data Collected in April 2010 from Indian River Bay, Delaware: Open-File Report 2011-1039, U.S. Geological Survey, Reston, VA.Online Links:
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.0001. Longitudes are given to the nearest 0.0001. Latitude and longitude values are specified in Degrees and decimal minutes.
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.
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. On this cruise, none of that information was filled in.
The three numbers at the end refer to initial tide correction at start-of-line, initial draft correction at start-of-line and sound velocity.
FIL: Raw format file.
ELL: Ellipsoid information. The name of the ellipsoid followed by the semi-major axis in meters and the flattening ratio.
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 Lowrance GPS data.
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 offsets were recorded for device 0 during this data collection.
LIN: planned line data follows in the format "LIN nw" where nw=number of waypoints.
PTS: planned line waypoints in the format "PTS x y" where x=waypoint easting; y=waypoint northing.
***In this case, easting and northing UTM zone 18N, meters.
LBP: planned line begin point in the format "LBP x y" where x=x grid position; y=y grid position.
***In this case easting and northing, UTM Zone 18N, meters.
LNN X: planned line name where X is the line name
EOL: end of planned line
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 (0 for Lowrance) 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. During this survey these values are in UTM, Zone 18, 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 no available or invalid, 1=GPS fix, 2=Differential GPS fix, 3=GPS PPS Mode fix, 4=RTK fix, 5=RTK Float.
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 X 100; long=raw longitude X 100; alt=antenna altitude above ellipsoid (meters); utc=GPS time in the format HHMM.
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.
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 this survey, three different messages were recorded from the GPS: $GPGGA, $GPGLL and $SDDBT. These will be defined later.
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. The NMEA strings present in the HYPACK file are the $GPGGA, $GPGLL, $SDDPT and $SDDBT. These are defined as follows.
$GPGGA is GPS fix data in the format "$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 1 is a GPS fix, 2 is a DGPS fix, 3 is a PPS fix, 4 is a Real Time Kinematic fix, 5 is Float RTK, 6 is estimated (dead reckoning), 7 is manual input mode, 8 is simulation mode; 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.
Example of a general $GPGGA string:
$GPGGA,180707,3835.9291,N,07509.0955,W,1,10,1.18,-6,M,,,,*0A
UTC Time = 180707
Latitude = 3835.9291 N
Longitude = 07509.0955 W
Fix Quality = 1
Number of satellites = 10
HDOP = 1.18 relative accuracy of horizontal position
Altitude = -6 meters above mean sea level
Height of geoid above WGS84 ellipsoid = not recorded
Time since last update = not recorded
Checksum = *0A.
$GPGLL is geographic position date in the format "$GPGLL, lat, lath, long, longh, t, vcheck" where 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; t=time in UTC in the format hhmmss.ss; vcheck=data valid and checksum.
Example of a general $GPGLL string: >$GPGLL,3835.9286,N,07509.0972,W,180708,A*31
Latitude = 3835.9286 N
Longitude = 07509.0972 W
UTC time = 180708
Checksum = A*31
$SDDPT is water depth in the format "$SDDPT, data_meters, offset *checksum"
Example: $SDDPT,1.6,0.0*50 Depth in meters = 1.6 Offset from transducer:0.0 Positive - distance from transducer to water line, or Negative - distance from transducer to keel$SDDBT is water depth below the transducer in the format "$SDDBT, depth, units (f=feet), depth, units (m=meters), depth, units (F=fathoms), *checksum"
Example: $SDDBT,5.2,f,1.6,M,0.8,F*0E
Depth in feet = 5.2
Depth in meters = 1.6
Depth in fathoms = 0.8
Checksum = *0E
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 the SDDPT definition was obtained from: <http://www.eye4software.com/products/gpstoolkit/nmea/>
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov
The purpose of these HYPACK navigation files in ASCII format is to archive all the raw HYPACK (VER 9.0.5.17) navigation data acquired during USGS Field Activity Number 2010-006-FA. These data can be used to supplement other data collected during this cruise.
Person who carried out this activity:
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov
The navigation system used was a Lowrance 480M with an LGC-2000 Global Positioning System (GPS) antenna. The antenna was located directly above the fathometer transducer mount point, but offset to the starboard by 2 meters from the resistivity streamer tow point. GPS data are assumed to be accurate within 10 meters on this survey.
All bathymetry values were acquired by the 200 kHz Lowrance fathometer. The fathometer was mounted on the starboard side of the R/V Knob, directly below the GPS antenna. The Lowrance manufacturer indicates the speed of sound used by the system to calcuate depth is 4800 feet/second. The depth values are not corrected for the approximately 0.2 m transducer draft. All depth values are assumed to be accurate to within 1 meter.
These files represent all the HYPACK navigation recorded during USGS Field Activity 2010-006-FA.
These are the original files recorded by the HYPACK navigation software. No additional checks or corrections have been made to these files.
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.
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov
Downloadable Data
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.
| Data format: | This WinZip (v. 14) file contains the raw HYPACK navigation files as well as the associated metadata files. in format ASCII Size: 6.6 MB |
|---|---|
| Network links: |
<http://pubs.usgs.gov/of/2011/1039/data/navigation/hypack/hypacknav_raw.zip> <http://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html> <http://dx.doi.org/10.3133/ofr20111039> |
The user must have software capable of uncompressing the zip file. To make the most use of the data, the user must be able to parse the ASCII files to extract the location and depth information.
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov