\n \n \n \n \n \n

\n Synopsis
		sftahspecbal < in.rsf > out.rsf xstart= tstart= verbose=1 ntaper=12 wagc=-1 pnoise=0.01 fmin=5 fmax=95 finc=5

\nTHIS PROGRAM WAS WRITEN, BUT NEVER SUCESSFULLY TESTED. RESULTS LOOK
\nPOOR, BUT UNABLE TO SPEND TIME ON THE ALGORITHM, I ADDED IT TO THE
\nREPOSOTORY AND HOPE TO RETURN TO WORK ON IT AGAIN... SOMEDAY!
\n
\ntah is the abbreviation of Trace And Header. Madagascar programs
\nthat begin with sftah are a designed to:
\n1- read trace and headers from separate rsf files and write them to
\nstandard output (ie sftahread)
\n2- filter programs that read and write standard input/output and
\nprocess the tah data (eg sftahnmo, sftahstack)
\n3- read tah data from standard input and write separate rsf files for
\nthe trace and headers data (ie sftahwrite)
\n
\nThese programs allow Seismic Unix (su) like processing in Madagascar.
\nSome programs have su like names.
\n
\nSome programs in this suite are sftahread, sftahgethw, ftahhdrmath,
\nand sftahwrite.
\n
\nThe sftahspecbal program is designed to improve the resolution and
\nappearance of the final imaged seismic section (ie after migration
\nand stack. When applied to noisey land data early in the processing
\nsequence (after surface consisntant decon and before migration and
\nstack) it attenuates noise on post migration and stack data. There
\nare several algorithms called spectral balancing, whitening, or
\nbroading. This program implenents a popular method. Each input
\ntrace is split into several narrow frequency bands by bandpass
\nfiltering. AGC is applied to rach frequency band, and the frequency
\nbands are summed. User parameters control the filter bands and the
\nAGC length. (reference http://www.xsgeo.com/course/spec.htm#content).
\n
\nEXAMPLE:
\n
\nsftahsort input=shots-receivers-23900_headfix.rsf \\
\nsort="xline:600,601 offset" \\
\n| sftahspecbal fmin=5 fmax=95 finc=5 wagc=.250 noise=.05 \\
\n| sftahwrite \\
\nverbose=1 \\
\nmode=seq \\
\noutput=specbalcmps.rsf \\
\n>/dev/null
\n
\nsfimage \n
\nIn this example the shot organized prestack data in the file
\nshots-receivers-23900_headfix.rsf are read in xline offset order by
\nsftahsort program. The headers are in the file
\nshots-receivers-23900_headfix_hdr.rsf, the headers parameter default.
\nThe headers are merged with the trace amplitudes and the tah data sent
\ndown the pipe for spectral balancing.
\n
\nsftahspecbal, spectral balance, was run by dividing the data into 5 Hz
\nfrequency bands, applying .25 second agc, summing the scaled bands,
\nand dividing by the sum of the scalars.
\n
\nSftahwrite writes the the trace data to specbalcmp.rsf and the headers
\nare written to the file specbalcmp_hdr.rsf. The output traces are just
\nsequentially written to the output file.
\nkls
\n
\nPARAMETERS
\n
\nfloat fmin= NULL
\n
\nCenter of the first frequency band.
\n\t
\n\n

\n \n \n \n \n \n

\n Parameters
		\n \n \n \n   float finc=5 \tfrequency band increment \n \n \n\n \n \n \n   float fmax=95 \tmaximum frequency band \n \n \n\n \n \n \n   float fmin=5 \tminimum frequency band \n \n \n\n \n \n \n   int ntaper=12 \t \n \n \n\n \n \n \n   float pnoise=0.01 \trelative additive noise level \n \n \n\n \n \n \n   floats tstart= \t [numtstart] \n \n \n\n \n \n \n   int verbose=1 \t \n \n flag to control amount of print \n 0 terse, 1 informative, 2 chatty, 3 debug \n \n \n \n\n \n \n \n   float wagc=-1 \t \n \n length of the agc window in seconds \n \n \n \n\n \n \n \n   floats xstart= \t [numxstart] \n \n \n

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