C 1 U. S. GEOLOGICAL SURVEY, WESTERN MARINE AND COASTAL TEAM C 2 CRUISE ID: G295SF SAN FRANCISCO BAY AREA C 3 YEAR COLLECTED: 1995 VESSEL: ROBERT GRAY C 4 SAMPLE INTERVAL: 2 MSEC SAMPLES PER TRACE: 512 OR 1024 C 5 RECEIVER: 150 METER LENGTH, 24 CHANNEL, ONE HYDROPHONE PER GROUP C 6 GROUP INTERVAL: 6.25 METERS SHOT INTERVAL: 6.25 OR 12.5 METERS C 7 SOURCE: ONE OR TWO 40 CUBIC INCH AIR GUNS C 8 CDP TRACE INTERVAL: 3.125 METERS RECORD LENGTH: 1.024 OR 2.048 SECONDS C 9 C10 IMPORTANT HEADER WORDS AND THEIR LOCATIONS: C11 NAME BYTE LENGTH DATA TYPE C12 LOCATION IN BYTES C13 FFID/SHOT 9-12 4 INTEGER C14 CDP NUMBER 21-24 4 INTEGER C15 YEAR 157-158 2 INTEGER C16 DAY 159-160 2 INTEGER C17 HOUR 161-162 2 INTEGER C18 MINUTE 163-164 2 INTEGER C19 SECOND 165-166 2 INTEGER C20 CDP-X (UTM) 181-184 4 INTEGER C21 CDP-Y (UTM) 185-188 4 INTEGER C22 UTM COORDINATES ARE EASTINGS AND NORTHINGS IN METERS IN UTM ZONE 10 C23 LATITUDE 189-192 4 FLOATING POINT C24 LONGITUDE 193-196 4 FLOATING POINT C25 LATITUDE/LONGITUDE VALUES ARE IN DECIMAL DEGREES C26 C27 THIS FILE CONTAINS 6 TO 12-FOLD STACKED MARINE SEISMIC REFLECTION DATA. C28 PRESTACK PROCESSING INCLUDED CDP SORTING, VELOCITY ANALYSIS, C29 DECONVOLUTION, BAND-PASS FILTERING (50-200 HZ), AGC, C30 NORMAL MOVE-OUT CORRECTION AND STACKING. C31 NO POST-STACK PROCESSING HAS BEEN APPLIED. C32 DATA FORMAT IS 32-BIT FLOATING POINT SEG-Y. C33 C34 FOR FURTHER INFORMATION CONTACT: C35 RAY SLITER OR PATRICK HART C36 U.S. GEOLOGICAL SURVEY, MS-999 C37 345 MIDDLEFIELD RD. MENLO PARK, CA 94025 C38 (415) 853-8300 C39 INTERNET: RSLITER@USGS.GOV OR HART@USGS.GOV C40 **************************************************************************