Open AccessPerformance of ERNE in particle flux anisotropy measurement
Author(s) -
E. Riihonen,
J. Torsti,
Anu-Hanna Anttila,
J. Kuusela,
M. Lumme,
Э. Валтонен
Publication year - 1996
Publication title -
annales geophysicae
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.522
H-Index - 93
eISSN - 1432-0576
pISSN - 0992-7689
DOI - 10.1007/s00585-996-0503-y
Subject(s) - anisotropy , spacecraft , detector , physics , particle (ecology) , angular resolution (graph drawing) , computational physics , resolution (logic) , flux (metallurgy) , shock (circulatory) , optics , astronomy , geology , computer science , materials science , mathematics , oceanography , combinatorics , artificial intelligence , metallurgy , medicine
The HED particle detector of the ERNEexperiment to be flown on the SOHO spacecraft is unique compared to the earlierspace-born detectors in its high directional resolution (better than 2°,depending on the track inclination). Despite the fixed view cone due to thethree-axis stabilization of the spacecraft, the good angular and temporalresolution of the detector provides a new kind of opportunity for monitoring indetail the development of the anisotropies pertaining, for example, to the onsetof SEP events, or passage of shock fronts related to gradual events. In order tooptimize the measurement parameters, we have made a preflight simulation studyof the HED anisotropy measurement capabilities. The purpose was to prove thefeasibility of the selected measurement method and find the physical limits forthe HED anisotropy detection. The results show HED to be capable of detectingboth strong anisotropies related to impulsive events, and smoother anisotropiesassociated with gradual events