Survey Identifier: RAPA02WT


Format Acronym: MGD77
Data Center File Number: 15040200
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): D.FORSYTH
Project: RAPA LEG 2
Funding: NSF
Survey Departure Date (yyyymmdd): 19901218
Port of Departure: MANZANILLO, MEXICO
Survey Arrival Date (yyyymmdd): 19910105
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: +20
Bottommost Latitude: -28
Leftmost Longitude: -115
Rightmost Longitude: -104
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 MIN. 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.
Number of Data Records: 25222

Min/Max Data Record:
Date: 1990 12 18
Latitude: -27.17616
Longitude: -114.47407
Bathymetry, 2- Way Traveltime: 001360
Bathymetry, Corrected Depth: 102.0
Magnetics Total Field, 1st Sensor: 297850
Magnetics Residual Field: -06103
Observed Gravity: 9780038
Free-Air Anomaly: -1041

Min/Max Data Record:
Date: 1991 01 05
Latitude: +19.07026
Longitude: -104.31482
Bathymetry, 2- Way Traveltime: 069333
Bathymetry, Corrected Depth: 5224.0
Magnetics Total Field, 1st Sensor: 405590
Magnetics Residual Field: +12440
Observed Gravity: 9791557
Free-Air Anomaly: +0880