The pointing system of the Herschel space observatory
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We present the activities carried out to calibrate and characterise the performance of the elements of attitude control and measurement on board the Herschel spacecraft. The main calibration parameters and the evolution of the indicators of the pointing performance are described, from the initial values derived from the observations carried out in the performance verification phase to those attained in the last year and half of mission, an absolute pointing error around or even below 1 arcsec, a spatial relative pointing error of some 1 arcsec and a pointing stability below 0.2 arsec. The actions carried out at the ground segment to improve the spacecraft pointing measurements are outlined. On-going and future developments towards a final refinement of the Herschel astrometry are also summarised. A brief description of the different components of the attitude control and measurement system (both in the space and in the ground segments) is also given for reference. We stress the importance of the cooperation between the different actors (scientists, flight dynamics and systems engineers, attitude control and measurement hardware designers, star-tracker manufacturers, etc.) to attain the final level of performance.
KeywordsHerschel space observatory Spacecraft Pointing Alignment Calibration Performance
We acknowledge the anonymous referee for his/her valuable comments and suggestions. The Herschel spacecraft was designed, built, tested, and launched under a contract to ESA managed by the Herschel/Planck Project team by an industrial consortium under the overall responsibility of the prime contractor Thales Alenia Space (Cannes), and including Astrium (Friedrichshafen) responsible for the payload module and for system testing at spacecraft level, Thales Alenia Space (Turin) responsible for the service module, and Astrium (Toulouse) responsible for the telescope, with in excess of a hundred subcontractors.
PACS has been developed by a consortium of institutes led by MPE (Germany) and including UVIE (Austria); KU Leuven, CSL, IMEC (Belgium); CEA, LAM (France); MPIA (Germany); INAF-IFSI/OAA/OAP/OAT, LENS, SISSA (Italy); IAC (Spain). This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI/INAF (Italy), and CICYT/MCYT (Spain).
- 1.Herschel/Planck ACMS Users’ Manual, H-P-4-DS-MA-001 (December 2006)Google Scholar
- 2.ASTR for Herschel/Planck User Manual, H-P-4-GAF-MA-0001, rev. 7 (October 2006)Google Scholar
- 3.Aussel, H.: Towards an accurate reconstruction of the Herschel pointing. Technical Report SAp-PACS-HA-0729-11, issue 1.0, CEA Saclay (November 2011)Google Scholar
- 4.Aussel, H.: PACS pointing jitter: the GYR view. Technical Report SAp-PACS-HA-0729-11, issue 1.0. CEA Saclay ((November 2011))Google Scholar
- 5.Aussel, H.: A first look into the STR catalog, CEA Saclay (27 July 2011)Google Scholar
- 6.Berrighi, G., Lorenzini, S.: Key Parameters for Herschel STR Catalogue Generation, Technical Note H-P-GAF-TN-0010, rev. 0 (4 February 2005)Google Scholar
- 8.Dungate, D.G.: Pointing Error Handbook, E S A, ESA-NCR-502 (Vol. 1), issue 1 (19 February1993)Google Scholar
- 9.Elfving, A., Rasmussen, I.: Herschel pointing accuracy and calibration procedures, SCI-PT-19552, rev. 1.3 (5 December 2003)Google Scholar
- 10.Feuchtgruber, H.: Herschel Guide stars – Assessment of Quality, PICC-ME-TN-040, rev. 1.0 (8 December 2011)Google Scholar
- 11.Feuchtgruber, H., Herschel, STR-A CCD: Sub-Pixel Structure, PICC-ME-TN-041, rev. 2.0 (26 March 2012)Google Scholar
- 12.Feuchtgruber, H.: Reconstruction of the Herschel Pointing Jitter, Technical Report PICC-ME-TN-042, rev. 1.0 (September 2012)Google Scholar
- 14.Kessler, M.F., Mller, T.G., Leech, K., et al.: The ISO Handbook, Volume I: ISO – Mission & Satellite Overview, ESA SP-1262 (2003)Google Scholar
- 15.Klaas, U., et al.: PACS Performance Verification Phase Plan, PICC-MA-PL-001, Issue 2.0 (2010)Google Scholar
- 16.Lutz, D. et al.: PACS photometer PSF, PICC-ME-TN-033, rev. 2.0 (4 April 2012) Available at http://herschel.esac.esa.int/twiki/pub/Public/PacsCalibrationWeb/bolopsf_20.pdf.
- 17.Marston, A. P., Sánchez-Portal, M.: the Herschel Pointing Working Group, Herschel Pointing Calibration Plan, HERSCHEL-HSC-DOC-1139, rev. 1.1 (2 April 2009)Google Scholar
- 19.Nielbock, M., et al.: PACS pointing calibration sources, PICC-MA-TN-003, rev. 1.1 (10 April 2008)Google Scholar
- 20.Nielbock, M., Müller, T., Klaas, U., et al.: The Herschel PACS photometer calibration - A time dependent flux calibration for the PACS chopped point-source photometry AOT mode. Exp. Astron., 35 (2013)Google Scholar
- 24.Sánchez-Portal, M., Marston, A. P., the Herschel Pointing Working Group: Herschel Routine Phase Pointing Calibration Plan, HERSCHEL-HSC-DOC-1622, rev. 0.1 (12 February 2010)Google Scholar
- 25.Sánchez-Portal, M., et al.: Herschel Pointing Calibration Report, HERSCHEL-HSC-DOC-1515, rev. 1.0, (25 November 2009).// Available at http://herschel.esac.esa.int/twiki/pub/Public/SpacecraftObservatoryWeb/pointing_calibration_report_v10.pdf
- 26.Stephenson, C.A.: Calculation of the 68th percentile of the Absolute Pointing Error, HERSCHEL-HSC-TN-2059, Issue 1.0, (December 2013)Google Scholar
- 27.Tuttlebee, M.: Herschel/Planck Star Tracker Performance Assessment and Calibration, PT-CMOC-OPS-RP-6435-HSO-GF, Issue 1.0 (August 2013)Google Scholar
- 28.Wertz, J. R. (Ed.): Spacecraft Attitude Determination and Control, Kluwer Academic Publishers (1978)Google Scholar