15 Aug
2020
15 Aug
'20
11:09 p.m.
Hello all
About my Zero offset synthetic VSP data, I thought something but I am not
sure about the effect of this issue. If I get rid of the first three traces
from the data before picking arrivals (deleting or killing), and continuing
next process steps, that give rise to any effect for results? If not so,
How should I write for getting rid of these three traces?
I added my screenshot (plus signs denotes picking)
Thank you
Best
Erdi
29 Sep
29 Sep
3:51 p.m.
New subject: seg2 conversion to su formats
Dear Sunix users:
Do you have any advice on the correct use of seg2segy? What am I not
understanding?
Any words of wisdom would be most helpful. Thanks in advance, Juan
PROBLEM
I am having difficulty converting SEG2 formatted files into SEGY and SU
files.
INSTRUCTIONS:
seg2segy 2.dat 1 > 2.sgy (BAD)
segyread tape=2.sgy >2.su (BAD)
suximage < 2.su & (BAD)
suximage < 2_clean.su (GOOD)
VISUAL RESULTS
Screenshot shows GOOD on left and BAD on right
SYSTEMS and SOFTWARE USED
cwp_su_all_44R4
CentOS8 linux box
cygwin (64) on Windows10.
FILES ATTACHED
2.dat (a SEG2 file from a Geometrics box)
2.sgy, 2.su
2_clean.su
Screenshot in png format of suximage-generated plots.
NOTES:
-For reference, I converted a test file (2.dat) successfully from SEG2
to SU format using sioseis under CentOS8
This "GOOD" file is 2_clean.su
-"BAD" means that I am able to obtain a plot which shows amplitudes that
seem too large-- with streaks
about the middle of the plot(file)
-"BAD" means that I can read the trace header values in HEX, the numbers
are correct
but that the data values seem too large.
-When I convert from seg2segy I get data value warnings (=0 and < 0),
and the data format appears to be in 4-byte integer
style.
-I have tried changed "scale" values in seg2segy.c and recompiling but I
still get poor results.
30 Sep
30 Sep
9:19 a.m.
New subject: seg2 conversion to su formats
Hi Juan,
I think you're right, it's probabaly related to the float samples of
your file instead of older geometrics which used integers.
Included, you'll find a modified seg2segy that we use to read DMT seg2
(float samples). I succesfully read your seg2file (it seems) with it.
You must compile it in 32 bits mode
On my Ubuntu box, I use
gcc -m32 -o seg2segy seg2segy.c
It also needs gcc-multilib to link proprely.
You also need to put the segykew.ord file somewhere (for me it's
/usr/local/bin, the code uses the PATH to find it).
seg2 format, unlike seg-y, is complicated and the header keywords are
user (manufacturer) defined. That's the use of the segykeyw.ord file, a
kind of dictionary to translate seg2 keywords into seg-y ones.
I hope that it will help.
By the way, seg2segy is the grand son (male ?) of a MS-DOS code by
Bennett, modified by Hervé Perroud (a former colleague in Pau, now
retired) and others. It clearly needs some update and cleaning... If
anyone is interested in this work, he/she is welcome !
D.
Le 29/09/2020 à 17:51, Juan Lorenzo a écrit :
Dear Sunix users:
Do you have any advice on the correct use of seg2segy? What am I not
understanding?
Any words of wisdom would be most helpful. Thanks in advance, Juan
PROBLEM
I am having difficulty converting SEG2 formatted files into SEGY and
SU files.
INSTRUCTIONS:
seg2segy 2.dat 1 > 2.sgy (BAD)
segyread tape=2.sgy >2.su (BAD)
suximage < 2.su & (BAD)
suximage < 2_clean.su (GOOD)
VISUAL RESULTS
Screenshot shows GOOD on left and BAD on right
SYSTEMS and SOFTWARE USED
cwp_su_all_44R4
CentOS8 linux box
cygwin (64) on Windows10.
FILES ATTACHED
2.dat (a SEG2 file from a Geometrics box)
2.sgy, 2.su
2_clean.su
Screenshot in png format of suximage-generated plots.
NOTES:
-For reference, I converted a test file (2.dat) successfully from SEG2
to SU format using sioseis under CentOS8
This "GOOD" file is 2_clean.su
-"BAD" means that I am able to obtain a plot which shows amplitudes
that seem too large-- with streaks
about the middle of the plot(file)
-"BAD" means that I can read the trace header values in HEX, the
numbers are correct
but that the data values seem too large.
-When I convert from seg2segy I get data value warnings (=0 and < 0),
and the data format appears to be in 4-byte integer
style.
-I have tried changed "scale" values in seg2segy.c and recompiling but
I still get poor results.
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2 comments
3 participants
participants (3)
-
Dominique ROUSSET -
Erdi Apatay -
Juan Lorenzo