Not all files contain the same HYPACK strings, but this list represents all the HYPACK strings represented in the files. These are the original files; no corrections have been made.
During UGSS cruise 2014-009-FA, the TELEDYNE RESON T20-P multibeam echosounder was tested; no data were collected for research and/or data analysis. Some fields within the HYPACK navigation files were setup for the T20-P and associated systems such as the ODIM Brooke Ocean Moving Vessel Profiler (MVP) 30. These fields contain usable data, however they were not used for any additional data analysis (Fields: DEV 3, DEV 2, TID, KTC, PRD).
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. 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 from the navigation parameters. NOTE: within some files the survey area is listed as "Offshore Delmarva Pennisula" which is incorrect. The survey area was offshore of Fire Island, Long Island, New York.
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. Blank if not present. Note: During survey 2014-009-FA geoid g2012a-CONUS.geo was used.
HVU: Horizontal and Vertical Units (meters).
TND: Survey time and date in UTC.
DEV 0: Indicates that lines collected with device designation 0 are lines of Differential Global Positioning System (DGPS) collected with the Ashtech BRG2 receiver. (The Ashtech BR2G was used as the primary antenna during JD299, starting with file 000_1804.299)
DEV 1: Indicates that the lines with device designation 1 are lines of Real Time Kinematic Global Positioning System (RTK-GPS) data collected with the Ashtech ProFlex 800 GPS RTK receiver. (The Ashtech ProFlex 800 GPS RTK receiver was used as the primary navigation receiver from JD292 through JD299 file 000_1253.299)
DEV 2: Indicates that the lines with device designation 2 are lines of center beam depth transmitted from the Reson T20-P multibeam echosounder via serial interface. *** The Teledyne Reson T20-P was tested during USGS cruise 2014-009-FA. The center beam depth information was stored in the Hypack raw files to be used as depth input for the MVP-30. ***
DEV 3: Indicates that the lines with device designation 3 are lines of NMEA Output.
DEV 4: Indicates that the lines with device designation 4 are lines of instrument information "DGPS_at_stern". Note: this device was labeled "Disabled" throughout the survey.
DEV 5: Indicates that the lines with device designation 5 are lines of Applanix POS M/V attitude and position system. Note: this device was labeled "Disabled" throughout the survey.
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.
DDT:identifies the device synchronizing the computer's time, where KTC is Kinematic Tide Corrections
PRD: Private Device Data, which has multiple formats depending on the type of device generating the data. For example, KTD is a Kinematic Tide Datum File that can be used to apply offsets to RTK values to establish corrected heights.
LIN 3: planned line data follows where X indicates the number of waypoints.
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 (e.g. 0 for Ashtech BRG2 DGPS) 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 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 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.
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 2014-009-FA there were several different messages were sent from the GPS systems. These message strings will be defined below. ($ECDPT is depth below transducer)
TID: Tide correction in the format "TID dn t dc" where dn=device number, t=time tag (seconds past midnight), dc = draft correction.
KTC: Describes how HYPACK records water levels (tide corrections) when using RTK where “KTC dn t nv eh lh u kval offset draft final” where dn = device number, t=time tag (seconds past midnight, matches GPS position), nv=number of values, eh= WGS84ellipsoidal height (from GPS), lh= local ellipsoidal height (on local ellipsoid), u=undulation, kval= K value, offset= antenna offset, draft=draft correction, final=final tide.
EC1: Echo sounding (singe frequency) in the format "EC1 dn t rd" where dn=device number, t=time tag (seconds past midnight), rd=raw depth. The center beam of the Teledyne RESON T20-P was used as input for the depth measurement. *** Teledyne Reson T20-P was tested during USGS cruise 2014-009-FA. ***
GYR: Gyro data (heading) in the format "GYR dn t h" where dn=device number, t=time tag (seconds past midnight), h=heading.
HCP: Heave Compensation in the format "HCP dn t h r p" where dn=device number, t=time tag (seconds past midnight), h=heave in meters, r=roll in degrees (+ port side up), p=pitch in degrees (+ bow up).
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 (National Marine Electronics Association) NMEA strings $GPGGA, $ECDPT, $ECDBS, $GPALM are stored in HYPACK files. (Some erroneous messages with the following strings appear within some files: $GP,GGA $444GP, $PCSI, $GPG1G.) 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 hemisphere; q=fix quality where 0=fix not available or invalid; 1=GPS fix; 2=Differential GPS fix; 3=GPS PPS Mode fix; 4=RTK fix; 5=RTK float; 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: $GPGGA,173356.00,4204.848996,N,07036.929067,W,4,09,01.1,00003.278,M,-028.888,M,01,0000*56 UTC Time = 173356 Latitude = 4204.848996 N Longitude = 7036.929067 W Fix Quality = 4 (indicates RTK) Number of satellites = 9 HDOP = 01.1 relative accuracy of horizontal position Altitude = 3.278 meters above mean sea level Height of geoid above WGS84 ellipsoid = -28.888 meters Time since last update = 01 Checksum = *57.
$ECDPT is depth information in the format "$ECDPT, x.x, f, x.x, M, x.x, F*hh", where X.X is depth in feet, f=feet, x.x is depth in meters, M=meters, x.x, depth in fathoms, F=Fathoms, *hh= checksum.
Example:
$ECDPT,27.70,4.32,105.00*47, where 27.70 is depth in feet, 4.32 is depth in meters, and 105 is depth in fathoms, *47 is checksum.
$ECDBS is depth below the surface in the format "$ECDBS,x.x,f,x.x,M,x.x,F*hh" where x.x is depth in feet, f=feet, x.x is depth in meters, M=meters, x.x is depth in fathoms, F=fathoms, and *hh=checksum.
Example:
$ECDBS,27.60,f,8.41,M,4.60,F*1C, where 27.6 is depth in feet, 8.41 is depth in meters, 60 is depth in fathoms, and *1C is checksum.
$GPALM is GPS alamanac data in the format $GPALM, x.x, x.x,xx,x.x,hh,hhhh,hh,hhhh,hhhh,hhhhhh,hhhhhh,hhhhhh,hhh,hhh,*hh where x.x=total number of messages, x.x is message number, xx is satellite PRN number (01 to 32), x.x is GPS week number: date and time in GPS is computed as number of weeks from 6 January 1980 plus number of seconds into the week, hh is SV health, bits 17-24 of each almanac page, hhhh is eccentricity, hh is almanac reference time, hhhh is inclination angle, hhhh is rate of right ascension, hhhhhh is root of semi-major axis, hhhhhh is argument of perigee, hhhhhh is longitude of ascension node, hhhhhh is mean anomaly, hhh is F0 clock paramter, hh is F1 clock parameter, and *hh is checksum.
Example:
$GPALM,32,1,01,1815,00,1D99,4E,0C1C,FD3E,A10CEB,11F83A,4FB58A,645F0D,018,000*4E, where 32 = total number of messages, 1 = message number, 01 = satellite PRN number, 1815 = GPS week number, 00=SV health, 1D99 is eccentricity, 4E is Almanac reference time, 0C1C is inclination angle, FD3E is rate of right ascension, A10CEB is root of semi-major axis, 11F83A is argument of perigee, 4FB58A is longitude of ascension node, 645F0D is mean anomaly, 018 is F0 clock parameter, 000 is F1 Clock parameter, *4E is checksum.
