Survey Identifier: RAPA04WT
Format Acronym: MGD77
Data Center File Number: 15040202
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.SCHEIRER
Project: RAPA LEG 4
Funding: NSF
Survey Departure Date (yyyymmdd): 19910220
Port of Departure: EASTER ISLAND
Survey Arrival Date (yyyymmdd): 19910308
Port of Arrival: SAN DIEGO, CALIFORNIA
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: +33
Bottommost Latitude: -28
Leftmost Longitude: -118
Rightmost Longitude: -105
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: 83
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: DEPTHS CORRECTED FOR 5 METER SHIP DRAFT. GPS PRESENT 23 HRS/DAY, PROCESSED BY GEOLOGICAL DATA CENTER, SCRIPPS INSTITUTION OF OCEANOGRAPHY, NAVIGATION: DR CSE/SPD BETWEEN 10 MINUTE INTERVAL GPS FIXES, 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: 22986
Min/Max Data Record:
Date: 1991 02 20
Latitude: -27.14132
Longitude: -117.24187
Bathymetry, 2- Way Traveltime: 018960
Bathymetry, Corrected Depth: 1414.0
Magnetics Total Field, 1st Sensor: 299970
Magnetics Residual Field: -05031
Observed Gravity: 9779970
Free-Air Anomaly: -1194
Min/Max Data Record:
Date: 1991 03 08
Latitude: +32.70667
Longitude: -105.36627
Bathymetry, 2- Way Traveltime: 076133
Bathymetry, Corrected Depth: 5751.0
Magnetics Total Field, 1st Sensor: 400820
Magnetics Residual Field: +06645
Observed Gravity: 9795546
Free-Air Anomaly: +1284