Survey Identifier: HM6804
Format Acronym: MGD77
Data Center File Number: J1030002
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
Project: THE BASIC MAP OF SEA OF CONTINENTAL SHELVES
Survey Departure Date (yyyymmdd): 19680827
Port of Departure: TOKYO
Survey Arrival Date (yyyymmdd): 19681029
Navigation Instrumentation: LORAN.A,2S3,2S4
Geodetic Datum/Position: LORAN A,2S3,2S4
Bathymetry Instrumentation: 50KHZ,BEAM-WIDTH 15-DEGREE*2
Additional Forms of Bathymetric Data: ANALOG RECORD
Magnetics Instrumentation: PROTON MAG
Additional Forms of Magnetics Data: TOTAL INTENSITY CHART 6328M,6329M
Gravity Instrumentation: TSSG-H1,SENSOR:P1
Additional Forms of Gravity Data: GRAVITY ANOMALY CHART 6328G,6329G
Seismic Instrumentation: AIR GUN
Formats of Seismic Data: ANALOG RECORD
Topmost Latitude of Survey: +42
Bottommost Latitude: +35
Leftmost Longitude: +137
Rightmost Longitude: +143
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: 250
Reference Field Code: 03
Reference Field: DGRF
Method of Applying Residual Field: DIRUNAL CORRECITON 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: 9799910
Departure Base Station Description: NIIGATA
Arrival Base Station Gravity: 9801830
Arrival Base Station Description: AKITA
Additional Documentation: CRUISE NAME:AKITA YAMAGATA OKI AND SADO OKI, OBSERVER:A.TOKUHIRO,T.YANAGI AND Y.GANEKO, SAKATA :980087 MGAL HAKODATE:980391 MGAL, REDUCTION AND COMPILATION GRAVITY DATA HAVE BEEN MADE BY T.TAKEMURA, T.YANAGI, AND Y.GANEKO OF THE ASTRONOMICAL DIVISION. CONVERSION POTSDAM INTO IGSN 71 HAS CARRIED OUT BY Y.GANEKO. magnetics records follow bathy and grav; no times for magnetics.
Number of Data Records: 6947
Min/Max Data Record:
Date: 1968 08 27
Latitude: +34.98167
Longitude: +137.07029
Bathymetry, Corrected Depth: 16.0
Magnetics Total Field, 1st Sensor: 469300
Magnetics Residual Field: -06324
Observed Gravity: 9796902
Free-Air Anomaly: -0673
Min/Max Data Record:
Date: 1968 10 23
Latitude: +41.69757
Longitude: +142.25451
Bathymetry, Corrected Depth: 2247.0
Magnetics Total Field, 1st Sensor: 482800
Magnetics Residual Field: +05259
Observed Gravity: 9804072
Free-Air Anomaly: +1643