High spatial resolution measurements of interseismic deformation along major faults are critical for understanding the earthquake cycle and for assessing earthquake hazard. We propose a new remove/filter/restore technique to optimally combine GPS and InSAR data to measure interseismic crustal deformation, considering the spacing of GPS stations in California and the characteristics of interseis...

We consider the perturbation of parabolic operators of the form ∂t + P (x,D) by large-amplitude highly oscillatory spatially dependent potentials modeled as Gaussian random fields. The amplitude of the potential is chosen so that the solution to the random equation is affected by the randomness at the leading order. We show that, when the dimension is smaller than the order of the elliptic pseu...

NASA Tech Briefs, November 2010 yield this behavior. Previous work on mean-square error characterization for ML estimators has predominantly focused on additive Gaussian noise. This work demonstrates that the discrete nature of the Poisson noise process leads to a distinctly different error behavior. This work was done by Baris I. Erkmen and Bruce E. Moision of Caltech for NASA’s Jet Propulsion...

A simple proof is given for the convexity of log det(I +KX) in the positive definite matrix variable X ≻ 0 with a given positive semidefinite K 0. Convexity of functions of covariance matrices often plays an important role in the analysis of Gaussian channels. For example, suppose Y and Z are independent complex Gaussian nvectors with Y ∼ N(0,K) and Z ∼ N(0,X). Then, I(Y;Y + Z) = log det(I +KX)...

In a complete Chaotic radar ranging system, its effective range is often limited by the randomness of the chaotic signal itself and other transmission channel noises or interferences. In order to improve the precision and accuracy of radar ranging system, wavelet transform is proposed to remove different kinds of noise embedded in chaotic signals. White Gaussian noise, colored Gaussian noise as...

In this correspondence, block and convolutional coding for Gaussian minimum shift keying (GMSK) in additive white Gaussian noise (AWGN) channels is investigated. The performance improvement that can be obtained without an increase in bandwidth is found for block and convolutional codes with various block lengths and constraint lengths, respectively, when a simple suboptimal demodulation scheme ...

NASA Tech Briefs, November 2010 yield this behavior. Previous work on mean-square error characterization for ML estimators has predominantly focused on additive Gaussian noise. This work demonstrates that the discrete nature of the Poisson noise process leads to a distinctly different error behavior. This work was done by Baris I. Erkmen and Bruce E. Moision of Caltech for NASA’s Jet Propulsion...

In this paper a new method of modulation classification based on spectrogram analysis is described. The classification method can discriminate between various digital signal modulations such as FSK, BPSK, MSK, QPSK and QAM-16. This classification method is examined on signals corrupted by Gaussian noise, phase noise and on signals after their transmission through multipath Rayleigh fading chann...

In this paper, an estimation of the Gaussian noise variance based on observed (measured) maximums of subsets of samples is given. Circumstances of the measurement environment being limited, only maximums of subsets of samples are available and the non-constant variance of the Gaussian noise can be estimated. In the case of power line noise, the variance of the zero mean Gaussian noise is a peri...

Abetmct A concept of optimal surplus harmonies distribution in selective harmonic elimination PWM teehnique for multilevel inverters is introduced in this paper. There m e several performance indexes that fan he optimized in PWM inverters, e.g., distortion factor, current or voltage total harmonic distortion, or efficiency. Minimisation of magnetic noise is selected as an example here. Several ...