Started: 2021-06-24 12:28:25
Last activity: 2021-07-06 09:58:49
Topics:
laure.duboeuf@realtimeseismic.com
2021-06-24 12:28:25

I currently work on removing instrument response on a 1s seismometer.

I generate a dataless using PDCC software.

The overall sensitivity is of 468170 000.

However, the seismometer gain is of 400 and the digitizer of 1677720.

According to the definition given in the resp file manual, the overall
sensitivity is the product of all gains.

Here, 400 * 1677720 = 671 088 000

671 088 000 / 468 170 000 = ~1.43

So I have a ~1.43 factor (sqrt(2) between the overall sensitivity given by
PDCC and the sensitivity obtained from the product of all gains.

Do you have any idea to explain this factor?

My best

Laure Duboeuf

--------------------------------------------------------------------------

Dr. Laure Duboeuf, Senior Geophysicist

Microseismicity
RealTimeSeismic (RTS)

Phone: +33 (0)6 33 20 14 59

http://www.realtimeseismic.com/ www.realtimeseismic.com

Technopole Hélioparc

2, avenue du Président Pierre Angot
CS 8011 64053 PAU
FRANCE

--
L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
https://www.avast.com/antivirus

##### Attachments
• Mary Templeton
2021-07-06 09:58:49
Good morning Laure,

Each stage gain is associated with a specific frequency in the amplitude-frequency
curve. Each individual stage can specify its gain at a different frequency and PDCC
calculates the overall sensitivity (stage 0 in dataless SEED) at the sensitivity of the ADC
stage (stage 3) by default. This value is typically 0.05 Hz, which is great for a broadband
seismometer, but is not within the passband of a 1 Hz sensor. To get adjust the response
for short-period stations in PDCC, you’ll need to:

1) edit the stage 0 Frequency of Sensitivity to equal that of your sensor stage
3) Select "Recalculate Sensitivity" from the Tools pulldown menu, and
4) select “Launch”

Calculating the sensitivity in the passband of the sensor (as well as the datalogger)
should fix the discrepancy.

cheers,
Mary

On Jun 30, 2021, at 4:56 PM, laure.duboeuf<at>realtimeseismic.com (via IRIS) <pdcc-bounce<at>lists.ds.iris.edu> wrote:

I currently work on removing instrument response on a 1s seismometer.
I generate a dataless using PDCC software.

The overall sensitivity is of 468170 000.
However, the seismometer gain is of 400 and the digitizer of 1677720.
According to the definition given in the resp file manual, the overall sensitivity is the product of all gains.
Here, 400 * 1677720 = 671 088 000

671 088 000 / 468 170 000 = ~1.43
So I have a ~1.43 factor (sqrt(2) between the overall sensitivity given by PDCC and the sensitivity obtained from the product of all gains.

Do you have any idea to explain this factor?

My best

Laure Duboeuf

--------------------------------------------------------------------------
Dr. Laure Duboeuf, Senior Geophysicist
Microseismicity
RealTimeSeismic (RTS)
Phone: +33 (0)6 33 20 14 59
<image001.png>
www.realtimeseismic.com
Technopole Hélioparc
2, avenue du Président Pierre Angot
CS 8011 64053 PAU
FRANCE

Garanti sans virus. www.avast.com

----------------------
PDCC
Topic home: http://ds.iris.edu/message-center/topic/pdcc/ | Unsubscribe: pdcc-unsubscribe<at>lists.ds.iris.edu

Sent from the IRIS Message Center (http://ds.iris.edu/message-center/)
Update subscription preferences at http://ds.iris.edu/account/profile/

18:10:30 v.2078d232