Guralp Systems CMG-5TD User Manual
Page 36
Calibration
The accuracy of the results depends on both the amount of data you have
selected and on its sample rate. To obtain good-quality results at low
frequency, it will save computation time to use data collected at a lower
sample rate; although the same information is present in higher-rate streams,
they also include a large amount of high-frequency data which may not be
relevant to your purposes.
The bbnoisecal script automatically performs appropriate averaging to
reduce the effects of aliasing and cultural noise.
6.3.1 Sensor response codes
The table below shows the correct value to use in the Instrument response
field of the bbnoisecal dialogue, depending on the type of your instrument.
Sensor
Sensor type code
Units (V/A)
CMG-5TD, DC – 50 Hz response
DC-50
A
CMG-5TD, DC – 100 Hz response
CMG-5_100
A
CMG-5TD, DC – 200 Hz response
CMG-5_200
A
36
Issue D - April 2013