Only when using the EVALRESP option is the displacement assumed to be
nanometers (1e9). If you are using any other instrument type (polezero,
none, fapfile, ...) it uses to what the instrument response specifies.
None is actually a default and if an instrument response is not
specified in the "from" to "to" it will use "none". None is a array
with values of (1.0 +0.0i) in frequency-amplitude space or a constant
amplitude with no phase shift.
As I recall, doing a
SAC> transfer from polezero sub polezero_file to none freq f1 f2 f3 f4
where polezero_file is created by rdseed, the units are meters. The
scale is determined by the CONSTANT in this case and the units
(displcaement, velocity, ..) are determined by the number of zeros in
the polezero description.
Cheers,
Brian
Peter Goldstein wrote:
Jim is correct. The default for transfer is displacement in nanometers.
So, for example, transfer from "my_instrument_type" to none means that you
are deconvolving your instrument and converting to what is hopefully a good
representation of actual ground displacement in nanonmeters.
At 10:19 PM +0000 3/18/06, jim<at>okgeosurvey1.gov wrote:
I had similar problems with transfer, until
I realized that whatever version I used
none did NOT mean no seismometer=earth motion.
I think "none" refers to some kind of generic
displacement transducer.
I will try to rediscover the syntax I used
in going from CMG-3 and CMG-1 to earth motion.
The transform apparently succeeded. My syntax
definitaly did not include the word "none"
Jim Lawson
OK geol. survey Leonard
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