Spacecraft orbit evasion is an effective method to ensure space safety. In the spacecraft's orbital plane, non-cooperate target with autonomous approaching spacecraft may have a dangerous rendezvous. To deal this problem, optimal maneuvering strategy based on relative navigation observability degree proposed angles-only measurements. A maneuver model in plane constructed and measurement criteri...

This paper addresses the problem of Doppler frequency estimation in the presence of speckle and receiver noise. An ultimate accuracy bound for Doppler frequency estimation is derived from the Cramer-Rao inequality. It is shown that estimates based on the correlation of the signal power spectra with an arbitrary weighting function are approximately Gaussian distributed. Their variance is derived...

In this paper a new modified Cramer-Rao lower bound (MCRLB) for multipath time-delay estimation is developed for DS-CDMA systems. The lower variance bound of each estimated path delay is determined via computer simulations using the theoretical results, and it is compared with an efficient and practical delay estimation method, namely peak tracking with pulse subtraction. Simulation results sho...

The Fisher information matrix determines how much information a measurement brings about the parameters that index the underlying probability distribution for the measurement. In this paper we assume that the parameters structure the mean value vector in a multivariate normal distribution. The Fisher matrix is. then a Gramian constructed from the sensitivity vectors that characterize the first-...

The goal of this paper is to characterize the best achievable performance for the problem of estimating an unknown parameter having a sparse representation. Specifically, we consider the setting in which a sparsely representable deterministic parameter vector is to be estimated from measurements corrupted by Gaussian noise, and derive a lower bound on the mean-squared error (MSE) achievable in ...

Minimum-variance estimators for the parameter fnl that quantifies local-model non-Gaussianity can be constructed from the cosmic microwave background (CMB) bispectrum (three-point function) and also from the trispectrum (four-point function). Some have suggested that a comparison between the estimates for the values of fnl from the bispectrum and trispectrum allow a consistency test for the mod...

In a previous paper [1] we presented a method for atomic decomposition with chirped, Gabor functions based on maximum likelihood estimation. In this paper we present the Cramér-Rao lower bounds for estimating the seven chirp parameters, and the results of a simulation showing that our sub-optimal, but computationally tractable, estimators perform well in comparison to the bound at low signal-to...

The problem of estimating the frequencies, phases, and amplitudes of sinusoidal signals is considered. A simplified maximumlikelihood Gauss-Newton algorithm which provides asymptotically efficient estimates of these parameters is proposed. Initial estimates for this algorithm are obtained by a variation of the overdetermined YuleWalker method and a periodogram-based procedure. Use of the maximu...

Angle-of-arrival estimation is a widely used localisation method. However, multipath propagation leads to decreased performance. In this paper an expression for the CramerRao lower bound for angle-of-arrival estimation with a known transmitted signal in a two path environment is derived. The influence of array structure on the achievable accuracy and the capability of signal separation is inves...