Survey Identifier: L680BS
Format Acronym: MGD77
Data Center File Number: 06050036
Parameters Surveyed Code: 55505
File Creation Date (yyyymmdd): 19870612
Source Institution: USGS Branch of Pacific Marine Geology
Country: United States
Platform Name: Lee
Platform Type Code: 1
Platform Type: SHIP
Chief Scientist(s): MIKE MARLOW, ALAN COOPER
Project: N.BERING SEA
Survey Departure Date (yyyymmdd): 19800706
Port of Departure: DUTCH HARBOR,ALASKA
Survey Arrival Date (yyyymmdd): 19800801
Port of Arrival: NOME,ALASKA
Navigation Instrumentation: SAT/LRNC/GYCOMP/SPDLOG/DOPPSONAR/RHO-RHO
Geodetic Datum/Position: PRIM-SAT, SECOND-LORAN-C, DRS
Bathymetry Instrumentation: 3.5/12KHZ,1-4 SEC SWEEP,25/50 MS CESP
Additional Forms of Bathymetric Data: ANALOG RECORDS,MICROFILM
Magnetics Instrumentation: PROTON PRECESSION MAG-GEOMETRICS
Additional Forms of Magnetics Data: ANALOG RECORDS
Gravity Instrumentation: L&R S-53
Additional Forms of Gravity Data: ANALOG STRIP CHARTS
Seismic Instrumentation: 24-CHANN,2400M STREAMER,GUS 4200 DIG REC
Formats of Seismic Data: 14 SECTIONS MICROFILM, POST-NAV PLOT
Topmost Latitude of Survey: +66
Bottommost Latitude: +53
Leftmost Longitude: +179
Rightmost Longitude: -165
General Digitizing Rate of Bathymetry: 32
General Sampling Rate of Bathymetry: 1-4 SECOND
Bathymetric Datum Code: 00
Interpolation Scheme: NO INTERPOLATION, DATA INTERVAL 1-5 MIN. W/INFLECTIONS
General Digitizing Rate of Magnetics: 010
General Sampling Rate of Magnetics: 04
Magnetic Sensor Tow Distance: 0213
Reference Field Code: 04
Reference Field: IGRF-75
Method of Applying Residual Field: MEASURED MAGS-(IGRF75 + ANNUAL CHANGES)
General Digitizing Rate of Gravity: 10
General Sampling Rate of Gravity: 20
Theoretical Gravity Formula Code: 3
Theoretical Gravity Formula: IAG SYSTEM 1967
Corrections Applied: DRIFT CORR APPLIED START AND END
Departure Base Station Gravity: 9688584
Departure Base Station Description: DUTCH HARBOR, AK
Arrival Base Station Description: NOME, AK
Additional Documentation: BATH-DATA DIGITIZED MANUALLY BY USGS UNDER CONTRACT TO DEFENCE MAPPING AGENCY, HYDROGRAPHIC/TOPOGRAPHIC CENTER. DATA DIGITIZED FROM ANALOG RECORDS. DIG-, ITIZING INTERVAL VARIABLE, DEPENDING UPON GRADIENTS, BUT SAMPLES SHOULD BE, RECORDED AT LEAST EVERY 5 MIN.,WITH INFLECION POINTS. FOR INFOR CONTACT:, JON CHILDS, U.S.G.S. (703) 860-7241 OR (415) 856-7094, CDP RECORDED AT 2-MSEC,PROCESSED AT 4-MSEC. 1ST 10 SEC EDITED, STACKED, DECONVOLVED,FILTERED,DISPLAYED. DIGITAL SHOT-PT NAV, DIGITAL TIME/VEL PAIRS.
Number of Data Records: 14940
Min/Max Data Record:
Date: 1980 07 08
Latitude: +53.03430
Longitude: -179.99721
Bathymetry, 2- Way Traveltime: 000520
Bathymetry, Corrected Depth: 39.0
Magnetics Total Field, 1st Sensor: 491660
Magnetics Residual Field: -08320
Observed Gravity: 9813618
Free-Air Anomaly: -0498
Seismic Line Number: 01
Seismic Shot-Point Number: 50
Min/Max Data Record:
Date: 1980 07 28
Latitude: +65.11379
Longitude: +179.99502
Bathymetry, 2- Way Traveltime: 048570
Bathymetry, Corrected Depth: 3615.0
Magnetics Total Field, 1st Sensor: 579104
Magnetics Residual Field: +32391
Observed Gravity: 9823084
Free-Air Anomaly: +0932
Seismic Line Number: 21
Seismic Shot-Point Number: 6590