Survey Identifier: HT94T332

Format Acronym: MGD77
Data Center File Number: J1010081
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): FUMIO KUMASAKA
Project: 33TH AREA CONTINENTAL SHELF SURVEY (HEISEI6-FOURTH)
Funding: HYDROGRAPHIC DEP
Survey Departure Date (yyyymmdd): 19941014
Port of Departure: TOKYO,JAPAN
Survey Arrival Date (yyyymmdd): 19941104
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: +19
Bottommost Latitude: +15
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: -9298
Departure Base Station Description: JHDGO(TOKYO PORT)
Arrival Base Station Gravity: -9283
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 & the Hatijo data of Magnetic Observatory,JMA.
Number of Data Records: 695

Min/Max Data Record:
Date: 1994 10 26
Latitude: +15.04767
Longitude: +137.42068
Bathymetry, Corrected Depth: 3750.0
Magnetics Residual Field: +00000
Free-Air Anomaly: -0460

Min/Max Data Record:
Date: 1994 10 31
Latitude: +18.03217
Longitude: +140.01584
Bathymetry, Corrected Depth: 6300.0
Magnetics Residual Field: +00000
Free-Air Anomaly: +0540