HYPER-DOLPHIN HPD 00959 Submersible Conductivity-Temperature-Depth Profiler (CTD)

Last Modified: 2017-04-28
: HPD 00959
: Processed (DMO)-QCed
: Depth/Pressure, Temperature, Salinity, Dissolved oxygen

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CTD/DO measurement system equipped on the remotely operated vehicle "HYPER-DOLPHIN"
  The CTD/DO system mounted on the 3000m-class remotely operated vehicle (ROV) "HYPER-DOLPHIN" is mainly composed of two instruments: a primary detection element and a PC for control and collection.
  The primary detection element is consisted of SBE-19 SEACAT PROFILER CTD and SBE43 DO of Sea-Bird Electronics, Inc, installed horizontally under the main float of the front horizontal thruster of the vehicle. Its withstand depth is 4200m and its maximum depth of use is 4000m. Each parameter of conductivity, water temperature, pressure, and dissolved oxygen (DO) can be measured in 1Hz and is transmitted to the PC for control and collection onboard. , Record of each measurement data and ASCII conversions, data corrections, data management in the primary detecting element, time control, and other environmental settings can be conducted in the PC.
  SBE-19 SEACAT PROFILER CTD and SBE43 DO, Sea-Bird Electronics, Inc.
 Sensor   Measurement range   Accuracy   Model   S/N 
  Temperature    -5 to +35 deg-C    0.01 deg-C    SBE 19    1924638-3068 
  Conductivity    0 to 7 S/m    0.001 S/m 
  Pressure    0 to 6000 psi    0.02% of full scale range 
  Dissolved oxygen    0 to 15 ml/l    0.1 ml/l    SBE 43    0818, 0819 
  The data collection in each dive starts from just before the HYPER-DOLPHIN (hereafter, the vehicle) submerges and ends immediately after it comes up to the sea surface.
  Because of the installed position of the primary detecting element, actual observation depth of the CTDO will be approximately 1.3m higher than the depth of the sea bottom even when the vehicle is on the seabed. Water intake duct is extended by a vinyl tube ahead of the vehicle on the left to minimize the effect of disturbances by the vehicle.
  1-sec time interval data was treated with the contents equal to the SEASOFT software which is a following data processing module.
Module Function
DATA CONVERSION Converts raw data to pressure, temperature, conductivity, and oxygen.
FILTER Performs a low pass filter on conductivity to make the high frequency data smooth.
ALIGNCTD Advances temperature for 0.5 seconds compared with pressure to correct the measurement time difference.
DERIVE Computes salinity.
  The data available on this web site is 1-sec mean CTD/DO data integrated with the vehicle positioning data in latitude and longitude. The SSBL (Super Short Base Line) method is used to measure the vehicle's position, which requires transponder installed on the vehicle and an array of transducers equipped on the bottom of the mother ship. The position is measured by both phase lag measured from angles of received sound waves and distance calculated from travelling period of them. As for the measurement accuracy of SSBL, standard deviation of the horizontal measurement error is within 2.5% of slant range. Vertical profile of sound velocity is needed to calculate accurate distance from the travelling period. Therefore, the temperature measurement using XBT etc. of each sea area is executed.
  The vehicle positioning data was calculated by adding the relative distance to the mother ship's position. The simplified equation with the area-dependent coefficients every 30 degrees in latitude and longitude was applied to the distance (XY) to Lon/Lat conversion, which provided by Japan Coast Guard. Here, the original time interval of position data is more than 10 seconds. The noises remaining in the position data are manually eliminated and linearly interpolated when the speed calculated from adjacent two position data is greater than 3.0 knot which is the maximum operation speed of the vehicle. Moreover, noises remained in the depth, temperature, salinity, and oxygen data are visually checked and replaced to missing values only when the data seemed to be obviously abnormal.
  The CTDO system was not installed as the observation equipment, but installed as one of the navigation equipment to monitor the ambient environmental conditions of the vehicle. So, note that the calibration interval of the equipment is not especially provided and the calibration of the equipment is irregularly executed.
  After considering the accuracy of the sensors, the significant digit of data was changed as in the following list.
Data Raw (ASCII data) On this web site
Depth 0.001 [m] 0.1 [m]
Temperature 0.0001 [deg-C] 0.01 [deg-C]
Salinity 0.0001 [PSU] 0.01 [PSU]
Dissolved oxygen 0.00001 [ml/l] 0.1 [ml/l]
: HPD 00959
: Processed (DMO)-QCed
: Depth/Pressure, Temperature, Salinity, Dissolved oxygen

Observation Map

Imagery reproduced from ...


Data List

  File names
: HPD 00959
: Processed (DMO)-QCed

Submersible CTD Qced (HPD)_1sec

  1. Header part
No. Column Item Format Remarks
1 1 Header ID a1 fixed as '#'
2 3 - 37 Submersible vehicle a35 HYPER-DOLPHIN
3 39 - 48 Data ID a10 CTD
4 50 - 70 Cruise ID a21 NNYY-XX(_legx)
5 78 - 81 Dive number a4
  1. Data part
No. Column Item Unit Format Remarks
1 1 - 8 Date - i8 YYYYMMDD (LST)
2 10 - 15 Time - i6 hhmmss (LST)
3 17 - 26 Latitude degree f10.5 No sign for the northern hemisphere.
Negative for the southern hemisphere.
4 28 - 37 Longitude degree f10.5 No sign for the eastern hemisphere.
Negative for the western hemisphere.
5 39 - 48 Depth m f10.1 Convert from pressure.*
6 50 - 59 Temperature deg-C f10.2 ITS-90
7 61 - 70 Salinity PSU f10.2 PSS-78
8 72 - 81 Dissolved oxygen ml/l f10.1
9 83 - 92 Altitude m f10.1
10 94 - 103 Roll degree f10.1
11 105 - 114 Pitch degree f10.1
12 116 - 125 Vehicle heading degree f10.1
13 127 - 136 Timecode - i10
14 138 - 147 Port swing arm angle degree f10.1
15 149 - 158 Starboard swing arm angle degree f10.1
16 160 - 169 Frame grab - i10 1: single grab
2: series of 8
17 171 - 180 HDTV pan degree f10.1
18 182 - 191 HDTV tilt degree f10.1
19 193 - 202 CCD pan degree f10.1
20 204 - 213 CCD tilt degree f10.1
  1. Missing value is presented by '-999'.

* Approximately 0.2% error is included due to latitude information.

Related Information

Cruise Data Dive Data

Update History

An observation data was registerd.
An observation data was registerd.