Survey Identifier: HM6802
Format Acronym: MGD77
Data Center File Number: J1030001
Parameters Surveyed Code: 55513
File Creation Date (yyyymmdd): 19801222
Source Institution: HYDROGRAPHIC DEPT.
Country: JAPAN
Platform Name: MEIYO
Platform Type Code: 1
Platform Type: SHIP
Chief Scientist(s): TAKAHIRO SATO
Survey Departure Date (yyyymmdd): 19680530
Port of Departure: TOKYO
Survey Arrival Date (yyyymmdd): 19680630
Port of Arrival: TOKYO
Navigation Instrumentation: LORAN A,2S1.2S2.2S3.2H7
Geodetic Datum/Position: LORAN A,2S1.2S2.2S3.2H7
Bathymetry Instrumentation: 50KHZ,BEAM-WIDTH 15-DEGREE*2
Additional Forms of Bathymetric Data: ANALOG RECORD
Magnetics Instrumentation: PROTON MAG
Gravity Instrumentation: TSSG-H1,SENSOR:P1
Topmost Latitude of Survey: +42
Bottommost Latitude: +34
Leftmost Longitude: +139
Rightmost Longitude: +149
General Digitizing Rate of Bathymetry: 100
General Sampling Rate of Bathymetry: 1/SECOND
Assumed Sound Velocity: 15000
Bathymetric Datum Code: 07
General Digitizing Rate of Magnetics: 050
General Sampling Rate of Magnetics: 06
Magnetic Sensor Tow Distance: 0250
Reference Field Code: 03
Reference Field: DGRF
Method of Applying Residual Field: DIURNAL CORRECTION USING DATA OF OBSERVATORY
General Digitizing Rate of Gravity: 100
General Sampling Rate of Gravity: 00
Theoretical Gravity Formula Code: 3
Theoretical Gravity Formula: IAG SYSTEM(1967)
Reference System: SYSTEM JGSN75
Corrections Applied: DRIFT,ETOVOS
Departure Base Station Gravity: 9800370
Departure Base Station Description: SIOGAMA
Arrival Base Station Gravity: 9800370
Arrival Base Station Description: ONAHAMA
Additional Documentation: CRUISE NAME:TOKACHI TOHOKU OKI, OBSERVER: T.TAKEMURA,T.YANAGI,Y.GANEKO AND Y.KUBO, KURIHAMA 979798 MGAL HIRAIZUMI 980351 MGAL, REDUCTION AND COMPILATION GRAVITY DATA HAVE BEEN MADE BY T.TAKEMURA,T.YANAGI, AND Y.GANEKO OF THE ASTRONMICAL DIVISION. magnetics records follow bathy and grav; no times for mag OLD NGDC:56070001
Number of Data Records: 2048
Min/Max Data Record:
Date: 1968 06 02
Latitude: +34.87834
Longitude: +139.78661
Bathymetry, Corrected Depth: 40.0
Magnetics Total Field, 1st Sensor: 472200
Magnetics Residual Field: -02134
Observed Gravity: 9795522
Free-Air Anomaly: -2249
Min/Max Data Record:
Date: 1968 06 28
Latitude: +41.98429
Longitude: +148.03078
Bathymetry, Corrected Depth: 7775.0
Magnetics Total Field, 1st Sensor: 484700
Magnetics Residual Field: +02101
Observed Gravity: 9803072
Free-Air Anomaly: +1733