Help with instrument response removal

Users Mailing List Archive
1

Hi,
We have an TSA-SMA accelerometer from Kinemetrics. It has a metrozet TSA-100S sensore.

I have one big problem at the moment. I got the response files from the IRIS NRL site but I couldn’t figure which one to use (20v or 10v) and what kind of datalogger to use. More over, The Poles and zeros in the NRL RESP file are very different from the ones I got with the device. In the device datasheet there are no zeros.It looks like this:
A1 (rad/sec) : 3.0623e+13
R1 (Volts/g) : 5.245
Pole 1 (rads/sec) : -738.89 - 1179.38i
Pole 2 (rads/sec) : -738.89 + 1179.38i

Pole 3 (rads/sec) : 904.61 + 3871.94i

Pole 4 (rads/sec) : 904.61 - 3871.94i

In the device control application, it states that:
Full scale is 5.0 volts
sensitivity: 1.25 volts/g
and Number of ADC counts at +/- full scale, in counts: 8388608

I want to create a dataless seed file for this instrument, I tried by using PAZ as follows:
{‘gain’: 3.0623e+13,
‘poles’: [(-738.89 - 1179.38j),(-738.89 + 1179.38j),(904.61 + 3871.94j),(904.61 - 3871.94j)],
‘zeros’:[],
‘sensitivity’:8388608
}
But I’m not sure if this is correct and how to convert it to a dataless seed file.
Is it possible to have any assistant with this issue?

Thanks,
Ran

2

Hi Ran,

you could use ObsPy for that but I am not sure it is the right tool for the job. You might want to look into PDCC or similar tools:

http://www.iris.edu/manuals/pdcc_intro.htm

If you insist on using ObsPy the easiest way would be to read an already existing SEED file, modify its values and save it as a SEED file. Or convert to XSEED, do the modifications, and convert it back.

Whether or the response information is correct I do not know. You could contact the manufacturer.

All the best!

Lion

3

Thanks. I’ll try your suggestions.