R/V Knorr Calliope metadata file Wed 21/Jun/2006 21:05:13 Current time zone: GMT Standard Time ================================================== 12kHz depth ( Depth12) Format: xxxx.x (meters) Depth in meters obtained from the 12 kHz channel of the Knudsen bathymetry system. 5 meter transducer depth correction has been applied. __________________________________________________ 3.5kHz depth ( Depth35) Format: xxxx.x (meters) Depth in meters obtained from the Knudsen 3.5 kHz channel. 5 meter transducer depth correction has been applied. __________________________________________________ Air Temperature (Air_Temp) Format: xx.xxx (degrees C) Data is obtained from IMET_HRH primary sensor. __________________________________________________ EDO speed ( EDO_knt) Format: xx.xx (knots) Edo speedlog raw data converted to knots (millivolts*.004 = knots) __________________________________________________ EDO Speedlog ( EDO) Ship speed from Edo Speedlog - millivolts (millivolts*.004 = knots) __________________________________________________ Edo Depth String ( EDO_VDstr) __________________________________________________ Sea Surface Conductivity (SSCND) Falmouth Scientific TSG (OCM-S-212) sea surface conductivity Format: xx.xxxx (mmho/cm) OCM sensor is mounted in the bow chamber on the suction side of the clean sea water distribution pump, approximately 5 feet from the forward facing inlet at a depth of 15 feet. __________________________________________________ Sea Surface Temperature (SSTMP) Falmouth Scientific TSG (OTM-S-212) sea surface temperature Format: xx.xxxx (degrees C) OTM sensor is mounted in the bow chamber on the suction side of the clean sea water distribution pump approximately 5 feet from the forward facing inlet at a depth of 15 feet. __________________________________________________ GPS course over ground (GPS_COG) Course over ground (true) obtained from NMEA GPS_VTG data sentence. Format: xxx.x (degrees) __________________________________________________ Latitude (GPS_Lat) Latitude from GPS NMEA GGA data sentence formatted for display. Format: dd mm.mmm, N/S __________________________________________________ Longitude (GPS_Lon) Longitude from GPS NMEA GGA data sentence formatted for display. Format: ddd mm.mmm, E/W __________________________________________________ GPS Navigation data (GPS) Complete NMEA data output from the primary GPS receiver. WGS84 datum. The single digit following the position information in the GPGGA data string indicates the type of GPS fix as follows: 0=No valid fix; 1=Standard; 2=Differential; 3=P-Code NMEA GPGGA data sentence: Header , UTC of position, Latitude, N/S, Longitude, E/W, Quality indicator, Number of satellites in use, Horizontal dilution, Altitude, M (meters), Geoidal separation, M (meters), Age of differential data (secs), Differential reference station I.D. * checksum. (Lat & Lon values are "degrees minutes.decimal_minutes") NMEA GPVTG data sentence: Header, Course, T (degrees true), Course, M (magnetic), Speed, N (knots), Speed, K (km/hr) * checksum. NMEA GPRMC data sentence - not always available: Header, UTC of position fix, Status (A=valid, V=warning), Latitude, N/S, Longitude, E/W, Speed over ground (knots), Course over ground (True), Date (ddmmyy), Magnetic variation (degrees), E/W (Easterly variation subtracts from True course) __________________________________________________ GPS speed over ground (GPS_SOG) Speed over ground obtained from NMEA GPS_VTG data sentence. Format: xx.xx (knots) __________________________________________________ GPS type (GPS_TYPE) GPS position type (Std, Diff, P-Code) GPS position type indicator is obtained from the "quality indicator" included as part of the GPS NMEA GGA data sentence. __________________________________________________ Gyro heading (Gyro) Ship's heading obtained from the Gyro NMEA HEHDT data sentence. Format: xxx.x (degrees true) __________________________________________________ IMET Wind (IMET_WND) Format: X, Y, Total, Max, Min, LastVane, LastCompass, C1, C2 Wind X (m/sec), Positive for a stbd to port wind Wind Y (m/sec), Positive for a bow to stern wind Wind Total (m/sec), Averaged over previous minute Wind Max (m/sec, 15 sec interval), Wind Min (m/sec, 15 sec interval), Last Vane Reading (deg), Last Compass Reading (deg), Counter1 ("0"), Counter2 ("4") Note - Wind direction is not provided as a single quantity. Direction values are ship relative. The wind sensor does not have a compass installed (value should always be 0.0). __________________________________________________ IMET Barometric Pressure (IMET_BPR) Format: xxxx.xx (millibars) __________________________________________________ IMET longwave radiation ( IMET_LWR) __________________________________________________ IMET Precipation (IMET_PRC) Format: Last minute (mm/min), Last hour (mm/hr), Present level (mm) __________________________________________________ IMET Shortwave Radiation (IMET_SWR) Format: xxxx.x (watts/square meter) __________________________________________________ IMET Humidity & Temperature (IMET_HRH) Format: xx.xxx (%RH), xx.xxx (C) Note - Relative humidity (HRH) and Air temperature (Air_Temp) data are both obtained from this instrument. __________________________________________________ Knudsen bathymetry ( PKEL99) Depth data obtained from the Knudsen bathymetry system. Values have been corrected for transducer depth (5 meters). Format: Header ($PKEL99), time (hhmmss), 12 kHz depth (meters), 3.5 kHz depth (meters), Speed of sound (m/s), Lat (dd mm.mmm N/S), Lon (ddd mm.mmm E/W) Speed of sound is the value used by the Knudsen. It is entered manually and therefore is not necessarily correct. The time listed after the header should be nearly identical to the data item's time stamp - if it isn't, it means the Knudsen control computer is not synchronized to the ship's master clock. __________________________________________________ MetraByte #1 ( MByte1) __________________________________________________ NMEA Gyro (HEHDT) Ship's heading obtained from the Sperry Gyro. NMEA format: Header ($HEHDT), Heading (degrees), T (true), Heading (degrees), M (magnetic) * checksum. Version 2.20 (1/1/97) of the NMEA 0183 standard does not show magnetic heading in this data sentence and the validity of this item is questionable. __________________________________________________ Position from GPS receiver (Lat_Lon) Latitude & Longitude in decimal degrees. Format: +/-dd.dddddd +/-ddd.dddddd (N & E are "+") __________________________________________________ Relative humidity (HRH) Format: xx.xxx (%RH) Data is obtained from IMET_HRH primary sensor. __________________________________________________ Salinity (Salinity) Format: xx.xxxx Salinity (psu) calculated from sea surface temperature and conductivity data values in accordance with UNESCO 44. __________________________________________________ Sea surface fluorometer ( Fluorometer) WetLabs Wet-Star fluorometer located in the clean seawater system. Value reported in millivolts. Calibration must be done by interested science parties. __________________________________________________ Sound velocity ( SSV) Format: xxxx.xxxx (meters/sec) Surface sound velocity calculated from sea surface temperature and conductivity data values. Intermediate salinity values are calculated in accordance with UNESCO 44. __________________________________________________ True wind direction (Wnd_Dir) Format: xxx.x (degrees) Wind direction obtained from the IMET wind sensor and corrected for ship heading (gyro) plus ship course and speed (GPS SOG & COG). A 0 degree wind comes from the north. __________________________________________________ True wind speed (Wnd_Spd) Format: xx.xxxx (meters/sec) Wind speed obtained from the IMET wind sensor and corrected for ship heading (gyro) plus ship course and speed (GPS SOG & COG). __________________________________________________ True wind speed & direction (TWind) Format: Speed, Direction (meters/sec, degrees) Wind direction is given in meteorological terms; a 0 degree wind comes from the north. Ship speed and direction of travel are obtaned from GPS data (GGA SOG & COG). Sensor mounting orientation is corrected using the direction the ship is pointing obtained from the gyro (the ship is not necessarily moving in the direction its pointing). __________________________________________________ Turner fluorometer data (TF10_data) Fluorometer data from Turner Designs Model 10. Full scale = 1 volt (1000.00 from MetraByte A/D module). Exact value is not in agreement with instrument front panel meter due to the characteristics of the calibration resistor. Science party is responsible for recording comparative readings during the cruise if needed. __________________________________________________ Turner fluorometer range (TF10_Range) Fluorometer range setting from Turner Designs Model 10 (full scale = 1 volt). Actual values reported by the MetraByte A/D module (1000.00=1 volt) are not in agreement with the value indicated in the Turner manual due to the accuracy of the calibration resistor. Actual readings are per the following table (science party should check these values at some point during the cruise): Range Expected Actual X0 0.0v 000.10 X3.16 0.4v 488.60 X10 0.7v 831.00 X31.6 1.0v 9999.99 __________________________________________________ Wind XY velocities ( WND_XY) Meters/second - not corrected for ship motion. This data item is utilized by the true wind speed and direction calculations. __________________________________________________ Wyse (data) ( Wyse_data) __________________________________________________ __________________________________________________ Defined constants: CruiseID = KN182-14 WindSensorOffset = 0.0 __________________________________________________ __________________________________________________ Auxiliary information: Timestamp formats: The Calliope data collection application always uses GMT timestamp values regardless of the time zone setting of the application computer. However, new files are started at midnight local time and any date and time information included in data file headers is local time. If date or time values are included in data files as logged values, these will also be local values. The Calliope ".dat" data file headers indicate the local time zone setting when the file was started. Individual items in Calliope ".dat" data files are time stamped with two different formats. The first timestamp value is in the format used by Microsoft Visual Basic: the number of days since December 31, 1899 (Dec. 31 is day 1, not day 0). Its primary purpose is to provide a continuously increasing date and time indicator for use in data graphing applications. The VB format facilitates this for some applications but converting the number to the normal human readable form can be painful. The second timestamp value (hh:mm:ss format) in combination with the date in the file header may eliminate the need for this conversion. If not, the following may be helpful: 00.00 is 00:00:00 on Dec. 30, 1899. 00.50 is 12:00:00 (noon) on the same day. 35390.58333 is 14:00:00 May 15, 1998.