Issue |
Astron. Astrophys. Suppl. Ser.
Volume 131, Number 3, September 1998
|
|
---|---|---|
Page(s) | 539 - 548 | |
DOI | https://doi.org/10.1051/aas:1998285 | |
Published online | 15 September 1998 |
A strategy for fitting partially blended ridges in GONG solar p-mode spectra
Astronomy Unit, School of Mathematical Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, UK
Send offprint request to: M.J. Thompson
Received:
1
October
1997
Accepted:
18
March
1998
Observations of solar oscillations by the Global Oscillation
Network Group (GONG) using a network of telescopes deployed
around the Earth eliminate temporal aliases from the
oscillation power spectra to a very substantial extent,
making the measurement of oscillation mode parameters much
cleaner than with single-site observations. However, the
problem of spatial aliasing, which arises from the fact that
we see only one side of the Sun, still causes some problems.
We discuss some of the issues affecting the estimation of
medium-l solar acoustic mode parameters from the data obtained
by the GONG network, and in particular the contamination
by spatial leakage. We determine the areas in the
plane in which such leakage is a problem, and finally
we describe a method for improving the mode frequency estimation
in such regions, thus extending the range of modes for which
useful frequency estimates can be obtained.
Key words: methods: data analysis / sun: oscillations
© European Southern Observatory (ESO), 1998