Survey Identifier: HT93T301
Format Acronym: MGD77
Data Center File Number: J1010069
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: 30TH AREA CONTINENTAL SHELF SURVEY (HEISEI5-THIRD)
Funding: HYDROGRAPHIC DEP
Survey Departure Date (yyyymmdd): 19931004
Port of Departure: TOKYO,JAPAN
Survey Arrival Date (yyyymmdd): 19931021
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: +21
Bottommost Latitude: +17
Leftmost Longitude: +137
Rightmost Longitude: +141
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: -8704
Departure Base Station Description: JHDGO(TOKYO PORT)
Arrival Base Station Gravity: -8704
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: 1391
Min/Max Data Record:
Date: 1993 10 08
Latitude: +17.94700
Longitude: +137.44750
Bathymetry, Corrected Depth: 3610.0
Magnetics Residual Field: -02550
Free-Air Anomaly: -0870
Min/Max Data Record:
Date: 1993 10 17
Latitude: +20.97100
Longitude: +140.01100
Bathymetry, Corrected Depth: 7280.0
Magnetics Residual Field: +00660
Free-Air Anomaly: +0520