LINE USGS - 23 U.S.G.S. OFFSHORE EAST COAST 1978 DIRECTION SHOT = 153 DEGREES SCALED STACK FIELD DATA FIELD PARTY : 2912 VESSEL : M/V CARINO DATE SHOT : MAY - SEP 1978 ENERGY SOURCE : AIR GUNS RECORDING INSTRUMENTS : DFS IV RECORDING FILTERS LOW : 8 HZ. 18 DB/OCT HIGH : 62 HX. 72 DB/OCT SAMPLE RATE : 4 MSEC. RECORD LENGTH : 12 SECONDS MULTIPLICITY : 48 FOLD STREAMER LENGTH : 3600 METER 48 TRACE STREAMER DEPTH : 13 METER AVERAGE SOURCE DEPTH : 6.4 METERS AIR GUN CAPACITY : 2000 CU. IN INLINE SHOT OFFSET : 368 METERS ANTENNA TO SOURCE OFFSET : 57 METERS GROUP CENTER INTERVAL : 100 M. NEAR 24 TRACES (2 GROUPS/TRACE) : 50 M. FAR 24 TRACES (1 GROUP/TRACE) SHOTPOINT INTERVAL : 50 METERS DIGITAL PROCESSING TRUE AMPLITUDE RECOVERY : GAIN REMOVAL ALPHA = 5.0 DB/SEC. T1 = 0 T2 = 4.5 SEC. TIME VARIANT DECONVOLUTION : DEPTHS 0-137 M. - 3 400 MSEC. FILTERS DEPTHS 138-244 M. - 2 400 MSEC. FILTERS DEPTHS OVER 244 M. - 3 200 MSEC. FILTERS TIME VARIANT SCALING : GATE LENGTH 500 MSEC. UNITY AND 2 TO 1 FAR TO NEAR OFFSET SCALERS START TIME = WB VELOCITY ANALYSIS : VELSCAN VELOCITY ANALYSIS SCATTERGRAMS AT 3 KM. INTERVALS NORMAL MOVEOUT CORRECTIONS : VELOCITY ANNOTATION ON SECTION HEADING OPTIMUM TRACE MUTING FIRST BREAK SUPPRESSION : VARIABLE COMMON DEPTH POINT STACK : 48 FOLD TIME VARIANT FILTERING : TIME(MS+WB) FILTER(HZ) 0 15 - 45 3000 12 - 30 5000 8 - 25 TIME VARIANT SCALING : GATE LENGTH = 200 MSEC. START TIME = WB UNITY SCALERS