sftahmakeskey (2.0-git)
Trace And Header MAKE Secondary KEY.

        sftahmakeskey < in.rsf > out.rsf pkey= verbose=1 skey=

tah is the abbreviation of Trace And Header. Madagascar programs
that begin with sftah are a designed to:
1- read trace and headers from separate rsf files and write them to
standard output (ie sftahread)
2- filter programs that read and write standard input/output and
process the tah data (eg sftahnmo, sftahstack)
3- read tah data from standard input and write separate rsf files for
the trace and headers data (ie sftahwrite)

These programs allow Seismic Unix (su) like processing in Madagascar.
Some programs have su like names.

Some programs in this suite are sftahread, sftahgethw, ftahhdrmath,
and sftahwrite.

The sftahmakeskey program will make a secondary key. You sometimes
need a secondary key to number the traces in a gather. For example
after sorting the data in iline,xline,offset you usually cannot
store the data using the offset key because the offset sampling is
irregular. sftahmakeskey can be used to build the cdpt header from
the iline and xline keys. Input pkey=iline,xline. The secondary
key (defined by skey) will start with 1 when a new iline,xline is
encounterred. As long as iline,xline does not change, the skey will
increase by 1 on each successive trace. When iline or xline changes,
skey will start agina with 1. The output data can be stored in a
file indexed by cdpt,xline,iline.


sftahread \
verbose=1 \
input=npr3_gathers.rsf \
| sftahmakeskey pkey=iline,xline skey=cdpt verbose=1 \
| sftahwrite \
verbose=1 \
label2="cdpt" o2=1 n2=24 n2=1 \
label3="xline" o3=1 n3=188 d3=1 \
label4="iline" o4=1 n4=10 d4=1 \
output=mappedgather.rsf \

In this example the cmp sorted prestack data, npr3_gathers.rsf, are
read by sftahread. The headers are in the file npr3_gathers_hdr.rsf,
the headers parameter default. The headers are merged with the trace
amplitudes and the tah data sent down the pipe for sftahmakeskey.
sftahmakeskey creates the cdpt header and sftahwrite creates a 4
dimensional file.

string pkey=

A comma seperated list of primary header keys to monitor to determine
gathers. The trace number in the gather is counted and put in the
skey header location.

string skey=
The name of the secondary key created by the program.
int verbose=1

flag to control amount of print
0 terse, 1 informative, 2 chatty, 3 debug

Used In