Last modified 15 years ago Last modified on 02/05/2009 03:02:58 PM

SH/SHM sensitivity file

For computing true amplitudes SH/SHM need to know the calibration gain numbers to be multiplied to the digital counts of each trace. From SHM version 2.4 on this information is stored in a sensitivity file, by default this is the file $SH_INPUTS/sensitivities.txt. This filename may be altered using the global setup file, parameter sensitivity_file.

The syntax of the sensititvity file is one entry per line:

<stream> <from-time> <to-time> <gain>

where <stream> is the stream name giving station, channel and component (or component wildcard ?) separated by hyphens, e.g. xyz-bh-z, <from-time> and <to-time> specify the time window where this calibration gain is valid (in SH time format) and <gain> gives the total calibration gain in (nm/s)/count. The time entries <from-time> or <to-time> may be specified as three dots ..., indicating that there is no upper or lower time boundary of the calibration information, respectively. So many entries of the sensitivity file may look like

bfo-bh-? ... ... 1.67

in this case telling that all three components of bfo, channel bh have a total gain of 1.67 (nm/s)/count for all times (neither upper nor lower time boundary given). Other may look like

gra1-bh-z ... 16-oct-1995_11:00 1.212652
gra1-bh-z 16-oct-1995_11:00 07-feb-1997_12:00 1.171863
gra1-bh-z 07-feb-1997_12:00 ... 1.206827

indicating that at station gra1 the equipment was changed on 16-Oct-1995_11:00 and on 7-Feb-1997_12:00 resulting in a changing calibration gain.

To migrate from a version prior to SHM 2.4 with seedcalib_...-files to the 2.4 sensitivity file use script $SH_UTIL/sensitivity_from_old_style.csh and redirect the output to a file to get the new sensitivity file from your existing seedcalib_...-files. If you do not have a sensitivity file yet then enter

$SH_UTIL/sensitivity_from_old_style.csh > $SH_INPUTS/sensitivities.txt 

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