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Kepler Guest Observer Program

Calibration

CALIBRATION OF KEPLER DATA

The interpretation of Kepler light curves requires a careful understanding of the properties of the photometer, observing sequence, standard pipeline processing of the data, formats of data products, noise and systematic effects within the data. In this segment of the GO webpage we provide details on calibration and data quality issues of immediate concern to GOs. Within the Pipeline webpage we provide an overview of the Kepler science data pipeline. Under the Data Analysis webpage, users will find information concerning science operations, data products, visualization and analysis software.

Observers who are attempting to analyze variability phenomena having amplitudes less than ~5 mmag peak-to-peak should pay particular attention to the information about pipeline conditioning of the data. For stars with long-period, low amplitude signals, the light curves provided from the pipeline software should be used with caution because the techniques used to mitigate systematic effects and eliminate instrumental artifacts caused by e.g., spacecraft roll, differential velocity aberration, and pointing drift and jitter may also reduce or remove legitimate astrophysical signals having timescales exceeding several days.

Users are strongly encouraged to review the following papers, a subset of the Kepler documentation, prior to working with the data. These papers describe the science operations, processing and characteristics of the light curves. Examples of "first light" science results, on topics other than exoplanet detection, are also listed. As our understanding of the instrument progresses, additional discussion of systematic error mitigation, data quality issues, and calibration will be provided. In addition to these peer-reviewed papers, the user is also directed to the first edition of the Kepler Instrument Handbook, produced by the Project, and the Data Release Notes, one set of notes for each data release, available at MAST.
 

OPERATIONS, PROCESSING, and DATA PROPERTIES

  1. KEPLER MISSION DESIGN, REALIZED PHOTOMETRIC PERFORMANCE, AND EARLY SCIENCE
    Koch, David G., etal, 2010, ApJ, 713, L79

  2. KEPLER SCIENCE OPERATIONS
    Haas, Michael R., etal, 2010, ApJ, 713, L115

  3. INSTRUMENT PERFORMANCE IN KEPLER'S FIRST MONTHS
    Caldwell, Douglas A., etal, 2010, ApJ, 713, L92

  4. OVERVIEW OF THE KEPLER SCIENCE PROCESSING PIPELINE
    Jenkins, Jon M., etal, 2010, ApJ, 713, L87

  5. THE KEPLER PIXEL RESPONSE FUNCTION
    Bryson, Stephen T., etal, 2010, ApJ, 713, L97

  6. INITIAL CHARACTERISTICS OF KEPLER SHORT CADENCE DATA
    Gilliland, Ronald L., etal, 2010, ApJ, 713, 160

  7. INITIAL CHARACTERISTICS OF KEPLER LONG CADENCE DATA FOR DETECTING PLANET TRANSITS
    Jenkins, J. etal, 2010 ApJ 713, 120

  8. PRELIMINARY ASTROMETRIC RESULTS FROM KEPLER
    Monet, David G., etal, 2010, ApJ, submitted


INITIAL DATA APPLICATIONS

  1. KEPLER ASTEROSEISMOLOGY PROGRAM: INTRODUCTION AND FIRST RESULTS
    Gilliland, Ronald L., etal, 2010, PASP, 122, 131

  2. PHOTOMETRIC VARIABILITY IN KEPLER TARGET STARS: THE SUN AMONG STARS -- A FIRST LOOK
    Basri, Gibor, etal, 2010, ApJ, 713, 155

  3. DISCOVERY OF A RED GIANT WITH SOLAR-LIKE OSCILLATIONS IN AN ECLIPSING BINARY SYSTEM FROM KEPLER SPACE-BASED PHOTOMETRY
    Hekker, S., etal, 2010, ApJ, 713, L187

  4. SOLAR-LIKE OSCILLATIONS IN LOW-LUMINOSITY RED GIANTS: FIRST RESULTS FROM KEPLER
    Bedding, T. R., etal, 2010, ApJ, in 713, L176

  5. ASTEROSEISMIC INVESTIGATION OF KNOWN PLANET HOSTS IN THE KEPLER FIELD
    Christensen-Dalsgaard, J., etal, 2010, ApJ, 713, L164

Following are links to the webpage subsections which describe the pipeline components and a variety of aspects of the data calibration.

 

PIPELINE PROCESSING

PIPELINE OVERVIEW:     The Kepler Data Processing Pipeline
CALIBRATION (CAL):     The CAL software component, which converts counts to calibrated pixels
PHOTOMETRIC ANALYSIS (PA)     The PA software component, which sums pixels within a defined aperture, to create light curves
PRE-SEARCH DATA CONDITIONING (PDC)     The PDC software component, which applies instrumental and systematic corrections, in preparation for transit-searching

 

CALIBRATION

PHOTOMETER RESPONSE:   Wavelength-dependent response function of the Kepler Photometer
SIGNAL-TO-NOISE PROPERTIES:   Systematics of the detected flux and associated noise
PIXEL RESPONSE FUNCTION: Properties of the detector pixels across the focal plane
ARTIFACTS:   Intrumental artifacts in the detector and light curves, mitigation strategies
BACKGROUNDS:   Instrumental and natural background level, background corrections
FLUX CALIBRATION:   Conversion of detected photoelectrons to incident flux
ASTROMETRY:   Image centroids and associated celestial coordinates


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Editor: Martin Still
NASA Official: Jessie Dotson
Last Updated: Jan 11, 2013
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