47,644 research outputs found
Robust observer design under measurement noise
We prove new results on robust observer design for systems with noisy measurement and bounded trajectories. A state observer is designed by dominating the incrementally homogeneous nonlinearities of the observation error system with its linear approximation, while gain adaptation and incremental observability guarantee an asymptotic upper bound for the estimation error depending on the limsup of the norm of the measuremen noise. The gain adaptation is implemented as the output of a stable filter using the squared norm of the measured output estimation error and the mismatch between each estimate and its saturated value
Decoherence - Fluctuation Relation and Measurement Noise
We discuss fluctuations in the measurement process and how these fluctuations
are related to the dissipational parameter characterising quantum damping or
decoherence. On the example of the measuring current of the variable-barrier or
QPC problem we show there is an extra noise or fluctuation connected with the
possible different outcomes of a measurement. This noise has an enhanced short
time component which could be interpreted as due to ``telegraph noise'' or
``wavefunction collapses''. Furthermore the parameter giving the the strength
of this noise is related to the parameter giving the rate of damping or
decoherence.Comment: 6 pages, no figures, for Okun Festschrift, Physics Report
Analysis of stochastic time series in the presence of strong measurement noise
A new approach for the analysis of Langevin-type stochastic processes in the
presence of strong measurement noise is presented. For the case of Gaussian
distributed, exponentially correlated, measurement noise it is possible to
extract the strength and the correlation time of the noise as well as
polynomial approximations of the drift and diffusion functions from the
underlying Langevin equation.Comment: 12 pages, 10 figures; corrected typos and reference
On the proper reconstruction of complex dynamical systems spoilt by strong measurement noise
This article reports on a new approach to properly analyze time series of
dynamical systems which are spoilt by the simultaneous presence of dynamical
noise and measurement noise. It is shown that even strong external measurement
noise as well as dynamical noise which is an intrinsic part of the dynamical
process can be quantified correctly, solely on the basis of measured times
series and proper data analysis. Finally real world data sets are presented
pointing out the relevance of the new approach
Robust Inference for State-Space Models with Skewed Measurement Noise
Filtering and smoothing algorithms for linear discrete-time state-space
models with skewed and heavy-tailed measurement noise are presented. The
algorithms use a variational Bayes approximation of the posterior distribution
of models that have normal prior and skew-t-distributed measurement noise. The
proposed filter and smoother are compared with conventional low-complexity
alternatives in a simulated pseudorange positioning scenario. In the
simulations the proposed methods achieve better accuracy than the alternative
methods, the computational complexity of the filter being roughly 5 to 10 times
that of the Kalman filter.Comment: 5 pages, 7 figures. Accepted for publication in IEEE Signal
Processing Letter
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