SOI Team Science: GOLF Intercomparison


o SOI ID: GI-0

o Technical Summary

o Comparable Projects / Datasets

o Team Members

o Relevant Publications

  • Technical Summary:

    Comparison of MDI data with GOLF data for mutual calibration as applicable. Because the MDI long-term stability is insufficient to be able to compare global Doppler averages with GOLF's measurements, the only planned intercomparison is the provision of MDI measurements of a suitable proxy for the magnetic field structures contaminating the GOLF signal. These GOLF magnetic proxy measurements will be part of the SOI Structure Program and included in the continuous low-rate telemetry. The required data processing therefore consists solely of extracting the GOLF magnetic proxy measurements from the low-rate telemetry, calibrating them, and producing a suitable dataset. The output dataset is a time series on uniform cadence of two-dimensional maps of the proxy values. The duration of the time series is the life of the mission, with no planned gaps. The cadence is to be determined; the current value is a tapered average at a rate of one per 20 minutes. The spatial resolution and mapping are also to be determined; the present plan is for boxcar averages of the values in the full-disc field into a 96*96 uniform grid, with only the pixels on disc reported. The estimated size of the data set is thus of the order of 1k values per minute, 1.5 M values per day, 500 M values per year. The manner in which the data are to be provided to the GOLF team is to be determined, as is the frequency of updates (probably not more than once per day nor less than once per month). Also requested are images at the same temporal and spatial resolution of either I2 or I2+I3. This quantity may be needed for the roll angle determination. If the Ic maps at 128*128 and the 20 time averages are adequate to distinguish between spots and non-spots, no additional quantity will be needed for the GOLF Intercomparison and the spatial grid for the magnetic proxy should be increased to 128*128.

  • Team Members:

  • Relevant publications:

    Proceeding papers for SOHO 6/GONG'98: In Structure and Dynamics of the Interior of the Sun and Sun-like Stars
    (Eds. S.G. Korzennik & A. Wilson), ESA SP- 418, ESA Publications Division,
    Noordwijk, The Netherlands, in press (1998):

    Tri-Phonic Helioseismology: Comparison of Solar p Modes Observed by the
    Helioseismology Instruments Aboard SOHO

    T. Toutain, T. Appourchaux, F. Baudin, C. Fröhlich, A. Gabriel, P. Scherrer,
    B.N. Anderson, R. Bogart, R. Bush, W. Finsterle, R.A. García, G. Grec, C.J. Henney,
    J.T. Hoeksema, A. Jiménez, A. Kosovichev, T. Roca Cortés, S. Turck-Chièze,
    R. Ulrich and C. Wehrli

    Solar Physics, 175, 311-328 (1997)

    This page last revised July 22, 1998.

    Please address comments and questions to the Team Coordinator.

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