Survey Identifier: HT94T314

Format Acronym: MGD77
Data Center File Number: J1010076
Parameters Surveyed Code: 55500
File Creation Date (yyyymmdd): 19980123
Source Institution: HYDROGRAPHIC DEPARTMENT
Country: JAPAN
Platform Name: TAKUYO
Platform Type Code: 1
Platform Type: SHIP
Chief Scientist(s): SHIGERU KASUGA
Project: 31TH AREA CONTINENTAL SHELF SURVEY (HEISEI6-FIRST)
Funding: HYDROGRAPHIC DEP
Survey Departure Date (yyyymmdd): 19940415
Port of Departure: TOKYO,JAPAN
Survey Arrival Date (yyyymmdd): 19940502
Port of Arrival: TOKYO,JAPAN
Navigation Instrumentation: GPS/LORAN-C
Geodetic Datum/Position: INTEGRATED NAVIGATION SYSTEM
Bathymetry Instrumentation: SEA-BEAM BATHYMETRIC SYSTEM 12KHZ
Magnetics Instrumentation: PROTON MAGUNETMETER (PMM-100)
Gravity Instrumentation: ONBOARD GRAVIMETER SYSTEM (GMBH KSS-30)
Topmost Latitude of Survey: +22
Bottommost Latitude: +18
Leftmost Longitude: +134
Rightmost Longitude: +138
General Digitizing Rate of Bathymetry: 10
Assumed Sound Velocity: 1500
Bathymetric Datum Code: 05
General Digitizing Rate of Magnetics: 10
General Sampling Rate of Magnetics: 60
Magnetic Sensor Tow Distance: 252
Reference Field Code: 88
Reference Field: IGRF1990
General Digitizing Rate of Gravity: 10
General Sampling Rate of Gravity: 5
Theoretical Gravity Formula Code: 3
Theoretical Gravity Formula: r1967
Reference System: JGSN75
Corrections Applied: DRIFT & EOTVOS CORRECTION
Departure Base Station Gravity: -9304
Departure Base Station Description: JHDGO(TOKYO PORT)
Arrival Base Station Gravity: -9298
Arrival Base Station Description: JHDGO(TOKYO PORT)
Additional Documentation: Corection for sound velocity was applied to the seabeam data using tables for, the area No.53 in Echo-sounding Correction Tables NP 139 (Hydrographic Dept. UK,1980). The correction for time variations were carried out with the geomagnetic, variations at the Titisima data of Magnetic Observatory,JMA.
Number of Data Records: 1507

Min/Max Data Record:
Date: 1994 04 18
Latitude: +18.24850
Longitude: +134.92650
Bathymetry, Corrected Depth: 746.0
Magnetics Residual Field: -02050
Free-Air Anomaly: -0310

Min/Max Data Record:
Date: 1994 04 28
Latitude: +21.04500
Longitude: +137.51200
Bathymetry, Corrected Depth: 5850.0
Magnetics Residual Field: +01250
Free-Air Anomaly: +1130