Search Publications
Simultaneous retrieval of optical depths and scattering phase functions in Titan's atmosphere from Huygens/DISR data
Keller, H. U.; Grieger, B.; Rodin, A. V. +1 more
In January 2005, the Huygens probe will descent through Titan's atmosphere and the Descent Imager/Spectral Radiometer (DISR) will perform upward and downward looking observations at various spectral ranges and spatial resolutions. One of the subinstruments, the Upward Looking Visible Spectrometer (ULVS), measures the total downward radiation flux …
Identification of low frequency waves in the vicinity of the terrestrial bow shock
Walker, S. N.; Andre, M.; Balikhin, M. A. +1 more
In this paper, methods for the determination of the wave mode for low frequency waves based on observed differences in phase are reviewed. Examples, using measurements made in the terrestrial foreshock and magnetosheath, are used to illustrate the application of these methods. The use of advance methods such as NARMAX modelling or genetic algorith…
A spherical model for computing polarized radiation in Titan's atmosphere
Keller, Horst U.; Grieger, Björn; Salinas, Santo V. +1 more
The Huygens descent through Titan's atmosphere in January 2005 will provide invaluable information about Titan's atmospheric composition and aerosol properties. The Descent Imager/Spectral Radiometer (DISR) will perform upward and downward looking radiation observations at various spectral ranges and spatial resolutions. To prepare the DISR data i…
An advanced physical model of cometary activity
Fulle, M.; Szegő, K.; Rodionov, A. V. +2 more
We describe the present state of an advanced physical model aimed at the simulation of the environment of active cometary nuclei. The model can handle the complicated shapes of real cometary nuclei, and is ready to handle alternative assumptions concerning the nucleus composition and structure; its present version is based on the simple, but hithe…
The charge and velocity detector of the cosmic dust analyzer on Cassini
Kempf, S.; Srama, R.; Grün, E. +2 more
The cosmic dust analyzer aboard the Cassini spacecraft includes a charge and velocity detector which senses electric charges >10 -15 C of individual cosmic dust grains as they enter the instrument. Charge is an important property of each grain, because it affects its orbital dynamics and is a measure of its size. The duration and sha…
Remote sounding of the Martian dust from ISO spectroscopy in the 2.7 µm CO 2 bands
Lellouch, E.; de Graauw, T.; Feuchtgruber, H. +2 more
This paper presents a study of Martian aerosols based on the spectral observations near 2.7 µm. Simulations by Titov et al. [Planet. Space Sci. 48 (2000) 67] showed that the depth and the shape of saturated 2.7 µm band of atmospheric CO 2 are sensitive to the presence of aerosols. This allows one to determine the aerosol opt…
Energetic ions observed by Ulysses in the Jovian magnetosheath
Karanikola, I.; Anagnostopoulos, G.
In this paper we present a survey of energetic (>∼50 keV) ion and (>∼40 keV) electron measurements made in the Jovian magnetosheath by the (Heliospheric Instrument for Spectra, Composition and Anisotropy at Low Energies) experiment onboard Ulysses, during its flyby of Jupiter in February 1992. The most common characteristics of the magnetosh…
Cosmic ray intensity variation during a CME
Kandemir, G.; Geçkinli, M.; Firat, C. +2 more
The June 6, 2000 coronal mass ejection was an exceptional full halo, which made it possible to measure cosmic ray (CR) decrease with a simple experimental set-up. Variation in the local secondary cosmic ray density has been investigated by means of gamma rays. The experiment site was located in Istanbul (41.1N, 29.0E). CR electrons and slow gamma …
The effect of instrument limitations on the derivation of plasma flows from energetic ion anisotropies, with an application to Ulysses observations at Jupiter
Cowley, S. W. H.; Kolesnikova, E.
Plasma velocities determined from the anisotropies of energetic ions via the Compton-Getting effect have been important in studies of magnetospheric flows, particularly with regard to the magnetospheres of Jupiter and Saturn. In this paper we consider a range of issues concerned with the practical limitations of such measurements, and their effect…
More about the structure of the high latitude Jovian aurorae
Prangé, Renée; Pallier, Laurent
This study is based on the determination of a 'reference' main oval for Jupiter's aurora from a series of high-resolution images taken with the Faint Object Camera on board the Hubble Space Telescope in the H 2 Lyman bands centered near 1550 Å. We have taken advantage of the visibility of the northern auroral oval over a large range of …