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A nonlinear deterministic attitude estimator is developed. The estimator evolves directly on the special orthogonal group of rigid-body rotations. Similar estimators in the literature are characterized by constant estimator gains that amplify noise across all frequencies. The proposed method accounts for undesirable noise in exteroceptive measurements by incorporating a strictly positive real (SPR)...
Instrument pointing control systems mounted on spacecraft are inherently bandwidth-limited (due to lightly-damped flexible modes of the spacecraft) compared to the same system mounted to a rigid body (such as the ground). This work is concerned with the recovery of control bandwidth for space-based pointing systems via the application of μ-tip control, a passivity-based control methodology. First,...
Specific type IV radio burst with fine structure – quasi-periodic broadband pulsations (BBPs) and zebra pattern (ZP), recorded by OSRA spectrograph (Potsdam) on October 25, 1994, is considered as a source of information about electrons accelerated during solar flare. The type IV bursts are generated in coronal trap-like structures (coronal loops) accumulating accelerated electrons. BBP are considered...
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