Operations Specialists Paranal [calChecker] [HC monitor ] September 2013 The big picture I Why do we take calibrations? SCIENCE observations contain: • scientific information • OB: question by astronomer to the Universe • science observation: answer by the Universe Reinhard Hanuschik, QC Garching
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Operations Specialists Paranal [calChecker] [HC monitor]calCheckerHC monitor September 2013 The big picture I Why do we take calibrations? SCIENCE observations.
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Operations Specialists Paranal [calChecker] [HC monitor] September 2013
The big picture I
Why do we take calibrations?
SCIENCE observations contain:• scientific information
• OB: question by astronomer to the Universe• science observation: answer by the Universe
Reinhard Hanuschik, QC Garching
Operations Specialists Paranal [calChecker] [HC monitor] September 2013
Calibrations
CALIBs contain:• information about instrumental effects (ARC, FLAT, BIAS)• or atmospheric effects (STD flux, telluric)
SCIENCE reduction:• raw science calibrations with pipeline
Operations Specialists Paranal [calChecker] [HC monitor] September 2013
Calibrations
CALIBs:• clean, specialized measurement of certain instrumental effect• principle: input known see what the instrument does with this
input know about instrument
Operations Specialists Paranal [calChecker] [HC monitor] September 2013
Assumptions
Instrument is stable between night and daytime
• then: daytime calibrations sufficient
meaning: instrument conditions between day and night identical to acceptable level
if not (due to unexpected conditions): • science cannot be calibrated, lost
Operations Specialists Paranal [calChecker] [HC monitor] September 2013
Criteria
Two important quality criteria on calibrations
1. Completeness
If CALIB missing, or earlier/later CALIB exists but is inapplicable:
SCIENCE cannot be calibrated
CALIB completeness saving SCIENCE from last night
provided by calChecker
Operations Specialists Paranal [calChecker] [HC monitor] September 2013
Criteria
2. Quality
good quality valid measurement of instrumental conditions
valid: e.g. good flux and SNR
• overexposed flat: always bad• well-exposed ARC, but grating not in same position as for science:
bad
Also:• HC calibs check instrument status rather than individual science
CALIB quality ensures science of next night
provided by HC monitor
Operations Specialists Paranal [calChecker] [HC monitor] September 2013
The big picture II
Where in the dataflow is QC and daytime calib checks?
What is done on Paranal and in Garching?
Operations Specialists Paranal [calChecker] [HC monitor] September 2013
Garching
automatic process for every instrument:• calChecker every 30 minutes (tellTracker 15 min)• HC monitor every hour• running 24/7
output web pages identical for Garching (HQ) and Paranal (PL)• for convenience: mirror site ‘PL’ (replicated within 15 min)
Operations Specialists Paranal [calChecker] [HC monitor] September 2013
Garching
QC scientists:• each is responsible for about 4 instruments• 5/7 schedule, daytime only • no shift system, no backups! If sick/travel: only automatic services• in charge of configuration and maintenance of these tools
• e.g. calibration plan, scoring system
• review of past day results• analysis of calChecker issues• analysis of red scores on HC monitor and AB monitor• produce master calibrations
Operations Specialists Paranal [calChecker] [HC monitor] September 2013
Garching
If issues found:• fix them (if pipeline related), or ticket to developer
or• understand them (based on trending, experience etc.)
and• inform Paranal (mail, comment editors)
QC Garching has the first chance!
Operations Specialists Paranal [calChecker] [HC monitor] September 2013
Paranal
Daytime 7/7:• review (double-check) calChecker and HC monitor, to fill gaps
(weekends, issues in Garching evening/night) • react on Garching signals, coordinate actions, PPRS• pro-active: discover issues (never rely 100% on QC Garching, the
QC scientist might be sick or on holiday)• but no need for duplication:
if all scores are green, you can continue with the next instrument
no need for visual checks (unless HC system incomplete)! much better: check product monitors (P…) for details
Operations Specialists Paranal [calChecker] [HC monitor] September 2013