OPEN FILE REPORT 99-449

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SEG-Y Formatted Files
Seismic Reflection Data from the Gyre 1997 Cruise





Raw Lines
    This directory contains the raw, unprocessed data and seg-y headers collected on this cruise.  The files are named in the following format.  l1f1.sgy  where l stands for line followed by the line number and f stands for file with a number indicating which segment of the line is contained with in the file.  In this example l1f1.sgy would stand for line 1 file 1
 

Processed Lines
    These files contain the processed seismic data for the cruise.  The data were processed in Promax7.2 on a SGI Indy machine running OS IRIX 6.5.  Files were named in the following manner:  line1pro.sgy where line number is followed by "pro" to indicate processed lines. Processing was only performed on the longest subset of each line.  The following is a list of the flows performed on the raw seg-y data.

Flow 1 : load file and geometry
    2D Marine geometry spreadsheet
    Seg-Y Input
            File to input                                                                 Raw.seg-y
            Store Processing History                                            Yes
            Input Auxiliary Traces                                                Yes
            Get Channel Number from Trace Headers                   Yes
            Input Trace Format                                                        Get from Headers
            Display ensemble Formation                                        No
            Data Input Sample Rate                                                0.5 msec
            Maximum Time to input                                                variable
            Is this Stacked Data                                                    No
            Max Traces Per Ensemble                                            120
            Primary Sort Header Word                                        SHOT
            Input Primary Selection Choice                                Input all
            Input secondary selection Choice                                None
            Input global XY coordinates                                        No
            Use coordinate Scalar                                                    Yes
            Remap Seg-Y header Values                                     No
    Inline Geometry header Load
            water velocity                                                        1525
            Primary header to match database                        FFID
            Secondary Header to match database                    None
            Match by Valid trace Number                               NO
            Drop traces with Null CDP headers                      No
            Drop Traces with Null receiver Headers                 No
            Verbose Diagnostics                                                YES
    Trace header Math
         select Mode                                                            fixed equation Mode
              define header equation                                             FFID =CDP
    Disk Data Output
         output dataset file Name                                        geom
            New or existing file                                               New
            record length to output                                            0    (default parameter means include all)
            Trace sample format                                                16 bit
            Skip primary disk storage                                       No
Flow 2: Mute and Deconvolution
    Disk Data Input
          Read data from other lines/surveys                        No
                Select input file                                                      geom
                Trace read option                                                     Get all
                Read data multiple times                                         No
                Input trace headers only                                             No
                Override input datas sample interval                        No
    Trace Muting
               Reapply Previous mutes                                            no
                Mute time reference                                                  Time 0
                Type of Mute                                                             TOP
                Starting ramp                                                             30
                Extrapolate mute times                                               No
                Get Mute Times from Database                                Yes
                 Select Database                                                            Topmute        (Horizon picked ~300 ms above were bottom)
    True Amplitude recovery
                Apply spherical divergence corrections                     NO
                Apply inelastic attenuation correction                         NO
                Apply db/sec corrections                                                 YES
                         DB per second constant                                         6
                Apply time raise to a power corrections                         NO
                           Time power constant                                             NO
                Apply effect to data or remove function                     APPLY
                Maximum application Time                                         3500-4000
    Spiking Predictive decon
                Type of deconvolution                                                MIN PHASE SPIKING
                Decon Operator length                                                 80
                Operator white noise level                                             .1
                window rejection length                                                 2
                Time gate reference                                                     DATABASE FILE
                Select decon gate from Database
                        Select database                                                         DECON
                Output traces or filters                                                     TRACES
                Apply a band pass filter after decon                                     NO
                 Reapply mutes after decon                                             YES
   Disk Data Output
         Output dataset file Name                                        decon
            New or existing file                                               New
            record length to output                                            0    (default parameter means include all)
            Trace sample format                                                16 bit
            Skip primary disk storage                                       No
Flow 3 Stack
   Disk Data Input
            Read data from other lines/surveys                        No
            Select input file                                                      decon
            Trace read option                                                     sort
                     Primary Sort header word                                CDP
                    Secondary sort header word                            NONE
                   Sort order dataset                                                */
                    Presort in memory or disk                                Memory
            Read data multiple times                                         No
            Input trace headers only                                             No
           Override input datas sample interval                        No
    CDP Ensemble Stack
             sort order of input ensembles                                 CDP
             Method of trace summing                                        Mean
             root Power scalar for stack normalization             0.5
              Apply final datum statics after Stack                    Yes
            Has NMO been applied                                            No
    Disk Data Output
         Output dataset file Name                                        stack
            New or existing file                                               New
            record length to output                                            0    (default parameter means include all)
            Trace sample format                                               16 bit
            Skip primary disk storage                                       No
     Disk Data Input
            Read data from other lines/surveys                        No
            Select input file                                                      stack
            Trace read option                                                     get all
            Read data multiple times                                         No
            Input trace headers only                                             No
           Override input data's sample interval                        No
    Bandpass Filter
        Type of Filter                                                            single filter
        Type of filter specification                                        ormsby bandpass
         Phase of filter                                                            Zero
        domain of filter application                                        Frequency
         Percent zero padding for FFT                                    25
        Apply notch filter                                                        no
        Ormbsby bandpass filter values                                   4-8-100-150
        Reapply trace mute after filter                                    yes
    Seg-Y Output
        type of seg-y                                                            standard
               file name                                                            line1pro.sgy
        Retrieve history form header                                     yes
        copy reel header                                                          default
        job id for binary header                                               9999
        line number for binary header                                    9999
        desired trace format                                                    4 bit integer
        maximum time to output                                                    variable
        remap seg-y header values                                                no


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