Open AccessNoise characteristics of full‐disc helioseismic observations made by resonant scattering spectrometers
Author(s) -
Chaplin W. J.,
Elsworth Y.,
Isaak G. R.,
Miller B. A.,
New R.,
Pintér B.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.08920.x
Subject(s) - physics , noise (video) , helioseismology , spectrometer , computational physics , optics , spectral line , scattering , acoustics , magnetic field , astronomy , computer science , quantum mechanics , artificial intelligence , image (mathematics)
Resonant scattering spectrometers (RSSs) have been used to make high‐precision full‐disc helioseismic observations since the 1970s. They are capable of very high‐precision determinations of line‐shift, meaning that they are used to obtain precise velocity measurements, and, for suitably configured RSSs, the disc‐averaged longitudinal magnetic field (SMMF). In order to exploit fully the very extensive high‐precision data sets, it is essential to understand the noise characteristics of the instruments. This paper re‐examines the consequences for velocity and SMMF determinations of there being noise on the scattered light signals measured by an RSS. It presents a theoretical description, and analysis of simulations, which match well the noise variations found recently in both BiSON velocity and SMMF observations. It also outlines a method for using the differences between the power spectra of redundant channels to analyse instrumental noise characteristics.