Thread: writing GSE (IMS) and CSS files of impulses

Brian - thank you - that worked.

There seems to be a limit on the length of the filename in the command
"writecss filename" (15 or 16 characters). With too
long a filename it wrote an empty wfdisc file with
the warning message:

css-warning: Skipping wfdisc record because file name is too long...
css-warning: File name longer than 32 characters

My filename was 18 characters. I think it was made up to 32
in the names of the binary data (".w") files, which consist
of the filename I provide plus the station name (greedily five
characters) and then an 8-digit number, then ".w", which came to
33 characters. When I shortened my filename to 14 characters it
worked.

Once "writecss" had worked, "writegse" invoked by the same
macro also worked. I guess that the failed "writecss" had left
some memory not in a clean state, which tripped up "writegse"
- or does "writegse" also need SAC_USE_DATABASE set?

George - I haven't tried the Bristol version. Where do I get it?

Thanks to both.

Sheila.



On 09/28/2015 11:40 AM, savage<at>uri.edu wrote:

Sheila,

The error occurs as you have the “database” functionality” of sac turned off. CSS requires this functionality. I will update the error messages so others do not run into this same issue. Sorry if this was totally opaque.

To turn the database on use (depending on your shell)
bash% SAC_USE_DATABASE=1
or
csh% setenv SAC_USE_DATABASE 1

Examples:

Without database

% env SAC_USE_DATABASE=0 sac
SEISMIC ANALYSIS CODE [06/10/2014 (Version 101.6a)]
Copyright 1995 Regents of the University of California

SAC> funcgen impulse npts 2048 delta 0.05
SAC> writecss tmp
ERROR 1385: No worksets in memory.

With database

% env SAC_USE_DATABASE=1 sac
SEISMIC ANALYSIS CODE [06/10/2014 (Version 101.6a)]
Copyright 1995 Regents of the University of California

SAC> funcgen impulse npts 2048 delta 0.05
SAC> writecss tmp
SAC>

Brian


On Sep 28, 2015, at 5:04 AM, Sheila Peacock <sheila<at>blacknest.gov.uk> wrote:

I want to test the basic algorithms of another program that
reads only CSS-format data from arrays. Hence I generated
a set of impulses in SAC and tried to write them to a CSS-format
file with "writecss".

This failed with ERROR 1385: No worksets in memory.

The traces look OK with "p1", which I assume means that they
are "in memory".

I tried to write the same set of impulses into an IMS (GSE)
file with "writegse" (because I could convert this format to CSS
with another program) but this crashed SAC with a segmentation fault.

The commands to create the data were:

funcgen impulse npts 2048 delta 0.05

to create the basic impulse, then seven calls to "chnhdr" followed
by "write" to make seven traces with distinct station positions,
then "read" all seven traces in, then "writecss".

The header variables I set were:

kstnm
kcmpnm
stla
stlo
stel
nzyear, nzjday, nzhour, nzmin, nzsec, nzmsec
cmpaz, cmpinc

(stla, stlo and stel were all set to the values for an actual
array station and nzyear etc. all set to be today noon - i.e.
"realistic" values).

I am using SAC 101.6a on a CentOS5 64-bit Linux computer.
The errors occur whether I use the precompiled binary or a
locally-compiled version.

I have tested the two commands, "writecss" and "writegse"
with some "real" seismic data (obtained from IRIS and converted
to SAC from SEED format with rdseed) and I get the same errors,
so I don't think it's because I have not set a crucial
variable in the header. The "help" info does not mention which
variables need to be set for "writecss" and "writegse" to work.



Regards,
Sheila Peacock,
Blacknest.

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