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ESAC

Calibration management
What does that mean ? Do we need that ? Would we like it?
14 June 2006
Marcus G. F. Kirsch
Marcus Kirsch, XMM-Newton European Space Astronomy Center Page 1


menu
· X-ray calibration in the last century · Can we do better · Calibration management · Committee for X-ray calibration · Calibration mission scenario

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Marcus Kirsch, XMM-Newton European Space Astronomy Center Page 2


calibration in 20th century
· Balloons · Rockets observation time hours observation time hours

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· Satellites observation time years, decades
­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ UHURU COS-B Einstein (4 y) EXOSAT (3 y) ROSAT (9 y) RXTE (>11 y) Chandra (> 7 y) XMM-Newton (> 6 y) Integral (> 4 y) Swift (> 2 y ) Suzaku (> 1 y)

Marcus Kirsch, XMM-Newton European Space Astronomy Center Page 3


organisation
· Balloon and rocket experiments: construction, operation, calibration, data analysis one team · Satellite observatories:
­ development takes many years by institutes (instruments) and agencies (spacecraft) ­ operation is performed by agencies or other entities ­ calibration done by various entities need of tracking of information

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Marcus Kirsch, XMM-Newton European Space Astronomy Center Page 4


XMM, one of the last missions on paper

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· Pre launch documents partly exist only as paper copies · Ground calibration data is archived on CDs or hard disks in various institutes (if at all .....) · Calibration team completely exchanged after launch at ESA site · PI teams are big and not always clear on calibration strategy · Calibration targets firstly chosen by trial and error no clear concept or strategy · Calibration plan was refined and stratetigly designed only after some years of operation and some issues of the instruments (MOS patch, RGS effective area losses)

- Information flow is not secured 100 % - Calibration could have been coordinated better pre and in early mission
Marcus Kirsch, XMM-Newton European Space Astronomy Center Page 5


calibration accuracy
· · · · · · UHURU: ?? EINSTEIN: EXOSAT: ROSAT: Chandra: XMM: > > < < < 15 15 15 10 10 % % % % %

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- effective area gets bigger and bigger - statistical errors get very small - calibration for future science goals needs to be better than 1 %
Marcus Kirsch, XMM-Newton European Space Astronomy Center Page 6


can we do better
· Yes we can !!!

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­ More knowledge on calibration sources ­ Lessons learned ­ Currently 6 high energy missions in orbit that provide the chance to define a standard set of calibration targets for various instruments

· Agencies and institutes need to maintain better knowledge on calibration (issue clearly related to staff:

we need more experienced people from former missions on new missions, that remember what they did before)

· International standard on high energy calibration
­ Ground calibration standards ­ In orbit calibration standards

· Committee to control international calibration
Marcus Kirsch, XMM-Newton European Space Astronomy Center Page 7


Committee for X-ray calibration
· Defines standard ground calibration requirements · Defines standard orbit calibration targets · Reviews calibration of missions · May provide independent judgment of cross calibration status of a single mission with regard to the standard

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X

"certified by ICWG"
Marcus Kirsch, XMM-Newton European Space Astronomy Center Page 8


calibration management
· · Calibration is developed in cooperation with instrument PI team but implementation and coordination need to be independent Task and project management + quality control

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­ Agency or special PI institute responsible to track and archive calibration from development till end of mission (with sufficient manpower) ­ data archive and document archive for EVERY ground and in orbit cal measurement ­ Instrument can only be delivered for launch together with complete ground calibration ­ Mission committees (User groups) AND international standard

· ·

Yearly assessment on calibration by calibration committees Ground calibration assessment and comparison early in mission (before launch)
­ Verification of calibration components before launch ­ Cross calibration before launch ­ Set of targets in guarantee early ­ Set of targets to ­ Standard candle

·

Clear definition of in orbit calibration plan

same instrument configuration per defined period in order detection of instrument changes verify ground calibration observation and mandatory cross calibration

Marcus Kirsch, XMM-Newton European Space Astronomy Center Page 9


Possible calibration scenario
Scientific advisory board Mission committee Calibration standard committee

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Calibration Standards

Calibration requirements · objects · ground cal · contamination monitoring

Instrument PI
- Commitment to calibration requirements

Calibration PI
- calibration development - Implementation of calibration requirements

Calibration manager
Tracking of information Calibration archive calibration implementation central calibration provider calibration quality control mission cross calibration

Institute level

Marcus Kirsch, XMM-Newton European Space Astronomy Center Page 10