Search Publications
Effects of density, temperature and velocity gradients on inertial Alfven wave in cusp region
Agarwal, P.; Varma, P.; Tiwari, M. S.
The kinetic approach is used to evaluate the dispersion relation and growth/damping rate of inertial Alfven wave (IAW) with density, temperature and velocity gradients in an inhomogeneous plasma. The effects of gradient terms are studied for both the regions k⊥ρi<1 and k⊥ρi>1, where k⊥ i…
Apparent velocity estimation with P-SV ratio method
Liu, Yuewei; Li, Hongnan
The apparent velocity of the incident wave is an important parameter for simulating rotational ground motion with theoretical methods, but it is difficult to estimate effectively when there is only a single record. This paper discusses a P-SV ratio method based on elastodynamic theory in a multi-layer isotropic elastic half space. The apparent vel…
AC magnetic field measurements onboard Cross-Scale: Scientific objectives and instrument design
Sahraoui, Fouad; Dudok de Wit, Thierry; Kretzschmar, Matthieu +4 more
The ACB search-coil magnetometer for Cross-Scale will measure three components of the AC magnetic field up to 4 kHz, and one component up to 100 kHz. Turbulent and coherent magnetic field fluctuations in that frequency range play an important role in the acceleration, scattering, and thermalisation of particles. ACB will, together with the other i…
AKARI All Sky Survey: contribution from AGB stars to the far infrared flux from the Milky Way related to point sources outside the Galactic plane
Pollo, Agnieszka; Takeuchi, Tsutomu Tsutomu; Rybka, Piotr
Using data from the FIS AKARI All-Sky Survey, we make a first step towards the estimation of the contribution from Asymptotic Giant Branch (AGB) stars to the far-infrared (FIR) flux from the Milky Way. We estimate the contribution from the AGB, and post-AGB, stars to the total flux generated by point sources outside the Galactic plane. Additionall…
Studying the UV mg II Resonance Lines in 20 Be Stars
Antoniou, A.; Stathopoulos, D.; Danezis, E. +1 more
Using the GR model, we analyze the UV Mg II resonance lines in the spectra of 20 Be stars of different spectral subtypes, in order to detect the presence of satellite or discrete absorption components. The values of some physical parameters -- rotational, radial and random velocities, as well as the FWHM and the absorbed energy, as a function of t…
Generic procedure for designing and implementing plan management systems for space science missions operations
Chaizy, P. A.; Dimbylow, T. G.; Hapgood, M. A. +1 more
This paper is one of the components of a larger framework of activities whose purpose is to improve the performance and productivity of space mission systems, i.e. to increase both what can be achieved and the cost effectiveness of this achievement. Some of these activities introduced the concept of Functional Architecture Module (FAM); FAMs are b…
Science operations planning expertise: A neglected component of mission design
Chaizy, P. A.; Dimbylow, T. G.; Hapgood, M. A. +1 more
In this paper, Science Operations Planning Expertise (SOPE) is defined as the expertise that is held by people who have the two following qualities. First they have both theoretical and practical experience in operations planning, in general, and in space science operations planning in particular. Second, they can be used, on request and at least,…
Denoising observational data
Bourdin, Ph. -A.
Reducing noise caused by the instrumentation in observational data is a crucial step in data post-processing. A method is searched for that conserves most of the instrumental resolution and introduces as few methodical artefacts as possible. With such a method integrated in an observation sites software tool-chain, the resources spent for the gene…
The dynamics of the radiative zone of the Sun
Mathis, S.; Turck-Chièze, S.; Piau, L. +4 more
Helioseismology puts strong constraints on the internal sound speed and on the rotation profile in the radiative zone. Young stars of solar type are more active and faster rotators than the Sun. So we begin to build models which include different rotation histories and compare the results with all the solar observations. The profiles of the rotati…
Model of the Crustal Magnetic Field in the Martian Aurora Zone
Tong, Dong-Sheng; Chen, Chu-Xin
It is well known that aurorae are prominent on planets with a global magnetic field and occur where open magnetic field lines converge. The UV spectrometer used for investigating the characteristics of the atmosphere of Mars (SPICAM) on board the Mars Express made the first observation of auroral-type emission in the cusp region of the strong crus…