Survey Identifier: C3003
Format Acronym: MGD77
Data Center File Number: 01010301
Parameters Surveyed Code: 55513
File Creation Date (yyyymmdd): 19910219
Source Institution: Lamont-Doherty Geological Observatory
Country: United States
Platform Name: R/V Robert D. Conrad
Platform Type Code: 1
Platform Type: SHIP
Chief Scientist(s): NORMAN CHERKIS
Funding: NRL
Survey Departure Date (yyyymmdd): 19890210
Port of Departure: FORTALEZA, BRAZIL
Survey Arrival Date (yyyymmdd): 19890312
Port of Arrival: RECIFE, BRAZIL
Navigation Instrumentation: FURUNO,TRANSIT SAT,GPS
Geodetic Datum/Position: FURUNO DR BETWEEN SAT FIXES
Bathymetry Instrumentation: GENERL INSTRMNTS SEABEAM CENTER BEAM
Additional Forms of Bathymetric Data: SWATH ALSO COLLECTED BY URI
Magnetics Instrumentation: VARIAN V75 MAGNETOMETER
Gravity Instrumentation: BELL AEROSPACE BGM-3 GRAVITY METER
Seismic Instrumentation: DIGICON DSS-240
Topmost Latitude of Survey: -03
Bottommost Latitude: -16
Leftmost Longitude: -039
Rightmost Longitude: -030
General Digitizing Rate of Bathymetry: 10
General Sampling Rate of Bathymetry: VAR W/ DEPTH
Assumed Sound Velocity: 15000
Bathymetric Datum Code: 0
Interpolation Scheme: LOGGED ALL CNTR BEAM,CLOSEST TO 0 SECS. INTERP
General Digitizing Rate of Magnetics: 10
General Sampling Rate of Magnetics: 20
Magnetic Sensor Tow Distance: 0
Sensor Depth: 0
Horizontal Sensor Separation: 0
Reference Field Code: 88
Reference Field: IGRF-85
Method of Applying Residual Field: BILINEAR INTERP IN 1 DEG SQUARE
General Digitizing Rate of Gravity: 10
General Sampling Rate of Gravity: 0
Theoretical Gravity Formula Code: 8
Theoretical Gravity Formula: INTERNATIONAL 80
Reference System Code: 2
Corrections Applied: +.09545 MGAL/DAY, DC +18.3 MGAL
Departure Base Station Description: BARBADOS, 28 JAN 89
Arrival Base Station Description: RECIFE, 13 MAR 89
Additional Documentation: THEORETICAL GRAVITY FORMULA: Yo = 978.0327 * ( 1 + a - b ) where, a = .0053024 * sin( theta ) * sin( theta ), b = .0000058 * sin( 2 * theta ) * sin( 2 * theta ) . SAMPLING RATE IS APPROXIMATELY 1PING/6SEC BUT DOES VARY WITH DEPTH, Navigation for the multibeam bathymetry was adjusted to match bathymetry and, gravity in the survey area. Other data reported to have been collected on, this cruise were backscatter.
Number of Data Records: 43330
Min/Max Data Record:
Date: 1989 02 10
Latitude: -15.00351
Longitude: -38.36795
Bathymetry, 2- Way Traveltime: 000591
Bathymetry, Corrected Depth: 44.0
Magnetics Total Field, 1st Sensor: 245290
Magnetics Residual Field: -08410
Observed Gravity: 9779443
Free-Air Anomaly: -0737
Min/Max Data Record:
Date: 1989 03 12
Latitude: -3.67483
Longitude: -30.50382
Bathymetry, 2- Way Traveltime: 073348
Bathymetry, Corrected Depth: 5541.0
Magnetics Total Field, 1st Sensor: 265810
Magnetics Residual Field: +04430
Observed Gravity: 9785465
Free-Air Anomaly: +1345