Re: A problem to read a SEG-file using Fortran90 code on PC

abbad@xxxxxxx wrote:
Hi guys,

I have a problem to read a SEG-Y file (a file format used in
geophysics to store and process seismic data). The SEG-Y format
consists of three blocks separated by an IBG (InterBlock Gap). The
first block is written in EBCDIC on 3200 bytes and is followed after an
IBG by a 400-byte binary block. After a third IBG, there is another
binary block.

My questions are:

1) How to convert the EBCDIC code to real (through binary if necessary)
? I found that the ascii character from 0 to 20 corresponding to the
EBCDIC code don't exist in Windows and correspond to "blanck spaces".
2) How to jump the IGB gap when reading such a file?.
3) I wrote subroutines for binary to integer/real conversion and
vice-versa. are there any simple functions to do that for the special
formats of binary code (complement to "1" or not, on 4 or 8 bytes for
instance).
4) Do these functions depend on a specific Fortran compiler. If yes,
which one, running under windows, offers the best environement to
process EBCDIC and binary codes?.

thanks in advance and hope I get information from your past
experience with Fortran90.


The lazy approach would be to call the C language SEG-Y routines from CWP/SU

http://www.cwp.mines.edu/cwpcodes/index.html

rhb
.