Quality Control and
Data Processing

HC PLOTS
Piezo1
Piezo2
Piezo3
Piezo4
QC1 database (advanced users): browse | plot

The response of the four FT piezos is measured once a week during daytime. There are five response measurements for each piezo and for each of the four FT DITs in use: 0.84, 0.85, 3, and 10 ms.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
NONE	gravity_piezo..piezo1_response1_diff	difference between measured and stored response of piezo 1 and delay 1 [rad/Volts]	CAL		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Same for response 2, 3, 4, and 5, and for piezos 2, 3, and 4.

Trending

The differences between the measured and the stored values for the piezo response are trended.

Scoring&thresholds Response

The differences should be within -1 and +1 rad/Volt. If they are repeatedly outside then the stored values should be updated. Since there is no need for immediate action when thresholds are violated, scoring has not been implemented.

History

Introduced in September 2019.

Algorithm Response

The measured values can be found in the product header keys QC.FT.KAL.P<n>_RESP<m>, the stored values in ESO.FT.KAL.P<n>_RESP<m>, with <n>=1, 2, 3, 4 and <m>=1, 2, 3, 4, 5. The trended QC parameters are the differences measured - stored.