Universität zu Köln

Efimov, A. I., Lukanina, L. A., Samoznaev, L. N., Chashei, I. V., Bird, M. K. and Paetzold, M. (2017). Frequency fluctuations in the solar corona investigated with radio sounding experiments on the spacecraft ROSETTA and MARS EXPRESS in 2010/2011. Adv. Space Res., 59 (6). S. 1652 - 1663. OXFORD: ELSEVIER SCI LTD. ISSN 1879-1948

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Abstract

Coronal radio-sounding experiments were carried out using two-way coherent dual-frequency carrier signals of the ESA spacecraft ROSETTA in 2010 and MARS EXPRESS in 2010/2011. Differential frequency measurements recorded at both NASA and ESA tracking stations (sample rate: 1 Hz) are analyzed in this paper. Spectral analysis of the S-band, X-band, and differential frequency records has shown that the r.m.s. frequency fluctuation of each signal can be described by a radial power-law function of the form sigma(i) = A(i){R/R-circle dot)(-beta i), where i = s, x, sx. The ratio of the coefficients A(s) and A(x) differs from the expected theoretical value A(s)/A(x) = f(s)/f(x). This occurs because the X-band fluctuations underlie two-way propagation conditions while the S-band fluctuations are essentially the product of a one-way propagation experiment. The intensity of the frequency fluctuations decreases sharply at high heliolatitudes. The asymmetry of the frequency fluctuation intensity between ingress and egress is exploited to determine the solar wind speed at small heliocentric distances. (C) 2017 COSPAR. Published by Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Efimov, A. I. UNSPECIFIED UNSPECIFIED UNSPECIFIED Lukanina, L. A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Samoznaev, L. N. UNSPECIFIED UNSPECIFIED UNSPECIFIED Chashei, I. V. UNSPECIFIED UNSPECIFIED UNSPECIFIED Bird, M. K. UNSPECIFIED UNSPECIFIED UNSPECIFIED Paetzold, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-236568
DOI:	10.1016/j.asr.2017.01.001
Journal or Publication Title:	Adv. Space Res.
Volume:	59
Number:	6
Page Range:	S. 1652 - 1663
Date:	2017
Publisher:	ELSEVIER SCI LTD
Place of Publication:	OXFORD
ISSN:	1879-1948
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language R-CIRCLE-DOT; CIRCUMSOLAR PLASMA; WIND TURBULENCE; SIGNALS; CYCLE; SUN; SCATTERING; DENSITY Multiple languages Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/23656