Survey Identifier: RAPA03WT
Format Acronym: MGD77
Data Center File Number: 15040201
Parameters Surveyed Code: 55531
File Creation Date (yyyymmdd): 19
Source Institution: SCRIPPS INSTITUTION OF OCEANOGRAPHY
Country: USA
Platform Name: R/V T.WASHINGTON
Platform Type Code: 1
Platform Type: SHIP
Chief Scientist(s): P.LONSDALE
Project: RAPA LEG 3
Funding: NSF OCE89-18898
Survey Departure Date (yyyymmdd): 19910107
Port of Departure: EASTER ISLAND
Survey Arrival Date (yyyymmdd): 19910218
Port of Arrival: EASTER ISLAND
Navigation Instrumentation: SATNAV/GPS,AUTO LOG GYRO+2D DOPPLER SPD
Geodetic Datum/Position: LINEAR INTERP.BETWEEN ADJACENT FIXES
Bathymetry Instrumentation: SEABEAM VERTICAL BEAM (2&2/3 DEG) & 3.5
Additional Forms of Bathymetric Data: ANAL.REC,35MM FILM,DIGITAL MAG. TAPE
Magnetics Instrumentation: GEOMETRICS MAGNETOMETER MOD G-801/3
Additional Forms of Magnetics Data: ANAL.REC,35MM FILM,DIGITAL MAG. TAPE
Gravity Instrumentation: BELL BGM-3 METER
Additional Forms of Gravity Data: DIGITAL MAG TAPE
Seismic Instrumentation: NONE COLLECTED
Topmost Latitude of Survey: -27
Bottommost Latitude: -57
Leftmost Longitude: -124
Rightmost Longitude: -109
General Digitizing Rate of Bathymetry: 010
General Sampling Rate of Bathymetry: 1PING IN H2O
Assumed Sound Velocity: 15000
Interpolation Scheme: 1 MINUTE AVERAGES EXTRACTED FROM SEABEAM VERTICAL BEAMS
General Digitizing Rate of Magnetics: 010
General Sampling Rate of Magnetics: 06
Reference Field Code: 88
Reference Field: IGRF-1990
Method of Applying Residual Field: LIN.INTERP.POINTS WITHIN ONE DEGREE SQUARE
General Digitizing Rate of Gravity: 010
General Sampling Rate of Gravity: 01
Theoretical Gravity Formula Code: 3
Theoretical Gravity Formula: IAG SYSTEM 1967
Reference System Code: 3
Reference System: SYSTEM IGSN 71
Corrections Applied: EOTVOS AND METER DRIFT
Departure Base Station Gravity: 9785815
Departure Base Station Description: OCEANOGRAPHIC INST. MANZANILLO
Arrival Base Station Gravity: 9795355
Arrival Base Station Description: MAR FAC PIER SAN DIEGO
Additional Documentation: PROCESSED BY GEOLOGICAL DATA CENTER, SCRIPPS INSTITUTION OF OCEANOGRAPHY, DEPTHS CORRECTED FOR 5 METER SHIP DRAFT. SEA MARC II SIDE SCAN ALSO COLLECTED, NAV.: DR CSE/SPD BETWEEN 10 MINUTE INTERVAL GPS FIXES. GPS PRESENT 23 HRS/DAY, GRAVITY: 1 SEC METER COUNTS FILTERED WITH 25 POLE FILTER WITH 148 SEC DELAY. FREE AIR ANOMALY SPIKES PRESENT BECAUSE SAME FILTER NOT USED FOR NAV. NGDC has multibeam bathymetric data for this cruise, however the tracklines, found here in GEODAS may not exactly correspond to the multibeam data.
Number of Data Records: 53673
Min/Max Data Record:
Date: 1991 01 07
Latitude: -56.41674
Longitude: -123.18897
Bathymetry, 2- Way Traveltime: 001653
Bathymetry, Corrected Depth: 124.0
Magnetics Total Field, 1st Sensor: 347610
Magnetics Residual Field: -15054
Observed Gravity: 9790895
Free-Air Anomaly: -0958
Min/Max Data Record:
Date: 1991 02 18
Latitude: -27.14276
Longitude: -109.39133
Bathymetry, 2- Way Traveltime: 072187
Bathymetry, Corrected Depth: 5429.0
Magnetics Total Field, 1st Sensor: 514720
Magnetics Residual Field: +13444
Observed Gravity: 9822406
Free-Air Anomaly: +7420