On the measurement bias of low- solar -mode excitation parameters: The impact of a ground-based window function

¹ School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
² School of Science & Mathematics, Sheffield Hallam University, Sheffield S1 1WB, UK
³ Institut d'Astrophysique Spatiale, Université Paris XI, 91405 Orsay, France

Corresponding author: W. J. Chaplin, wjc@bison.ph.bham.ac.uk

Received: 20 August 2002
Accepted: 6 November 2002

Abstract

We present a study of the impact of a ground-based, multi-station window function on estimates of the power and damping of low- solar p modes extracted from fits to resonant structure in the frequency domain. The window functions come from six-site observations made by the Birmingham Solar-Oscillations Network (BiSON) over the 10-yr period beginning 1991 January. Two strategies were adopted. In the first, we used an 800-d time series of continuous observations made by the GOLF instrument on board the ESA/NASA SOHO satellite. These data were modulated by a variety of BiSON window functions, with fractional duty cycles ranging from ~0.4 to ~0.8, and the resulting series analyzed. In the second we generated artificial 10-yr time series and studied the effect on these of the complete BiSON window.