Hi, In the SU format, the bytes you use for inline and cross line numbers are allocated to SU use (see sukeyword -o ; d2 and f2 are floats in SU). Bytes # 189-192 and # 193-196 are inline/crossline numbers in segy rev1 for 3D post stack data. SU is not 3D fully capable and segywrite does not use them for segy rev0 output.
I tried this simple test.
suplane | sushw key=d2,f2 a=3,4 | segyhdrs | segywrite tape=plane.segy segyread tape=plane.segy | surange
tracl 1 32 (1 - 32) tracr 1 32 (1 - 32) offset 400 ns 64 dt 4000 d2 0.000000 f2 0.000000
:-(
I don't see any solution at the user level without modifying segywrite to introduce header remapping à la segyread.
Within SU, I suggest that you use other keywords to store the inline and cross line numbers (such as swdep/gwdep, 4 bytes integers) and apply header remapping to read the data in other software. Anyway, using bytes # 189-196 in SU will complicate data display.
suplane | sushw key=swdep,gwdep a=3,4 | segyhdrs | segywrite tape=plane.segy segyread tape=plane.segy | surange
tracl 1 32 (1 - 32) tracr 1 32 (1 - 32) offset 400 swdep 3 gwdep 4 ns 64 dt 4000
D.
Le 20/10/2022 à 01:35, tanahashi.m@gmail.com a écrit :
Dear all,
I have performed a time resample of some 500ns sampled 3D seismic data to 1ms intervals using the suresamp command as shown below, but was unable to transcribe the 189-192 bytes of the Inline and the 192-196 bytes of the crossline numbers.
segyread tape=Source3D.sgy|suresamp rf=0.5|segyhdrs|segywrite tape=Output3D_1ms.sgy
I solved this problem by using the ASCII input/output function for trace header on SeiSee, a free Windows software, to write out the header information of the original file and then write it into the header of the output file.
Is there a way to transcribe inline and crossline numbers using the SU function?
Manabu Tanahashi
Tsukuba, Japan
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