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Knowledge Base Question

Do the USArray TA data contain calibration signals?

IRIS Webmaster gravatar

IRIS Webmaster  staff  Nov. 13, 2013, 3:40 p.m.

Do the USArray TA data contain calibration signals? If so, when and where are they? What do they look like?

Gillian Sharer gravatar

Gillian Sharer  accepted answer  staff  Nov. 13, 2013, 3:46 p.m.

Calibrations on USArray TA data are run within a few days to weeks both after sensor installation and before sensor removal (if possible). The signal looks like large amplitude white noise with an abrupt start and end and lasts for about 2 hours. Two examples are illustrated below:

Calibration of TA.X47A
Figure 1: Calibration response on BH* channels of TA.X47A on 2011-12-16 14:25:39 UTC.

Calibration of TA.237A
Figure 2: Calibration response on LH* channels of TA.237A on 2011-12-12 16:16:51 UTC.