Bibcode
Boumier, P.; Martic, M.; Bocchia, R.; Dame, L.; Palle, P.
Bibliographical reference
(Helioseismology from space; Proceedings of the Interdisciplinary Scientific Commission E Meeting (ME.7) of the COSPAR 28th Plenary Meeting, The Hague, Netherlands, June 25-July 6, 1990. A91-34076 13-92) Advances in Space Research (ISSN 0273-1177), vol. 11, no. 4, 1991, p. 199-202.
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1991
Citations
0
Refereed citations
0
Description
The first data of a SOHO-GOLF type instrument are presented. The slopes
of the solar sodium lines profiles D1 and D2 and their variations with
the excursion of the working point are shown. Two methods of determining
the oscillation velocity are compared, one usually used with two-point
spectrometers and one using the four-point information. It is shown that
the second method gives spectra which are significantly less noisy in
the very low frequency range. For higher frequencies, terrestrial
atmospheric fluctuations alter the measurement, and as far as ground
based instruments are concerned, the four-point method loses its
efficiency if the magnetic modulation commutation time is not
significantly reduced.