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— It is well known that motor current is a nonsta-tionary signal, the properties of which vary with respect to the time-varying normal operating conditions of the motor. As a result, Fourier analysis makes it difficult to recognize fault conditions from the normal operating conditions of the motor. Time–frequency analysis, on the other hand, unambiguously(More)
This paper presents an analytic method for synthetic-aperture inversion when the measurements are corrupted with noise and clutter. We use microlocal analysis in a statistical setting to develop filtered-backprojection-type reconstruction methods. The inversion method is applicable in non-ideal scenarios, such as those involving arbitrary source(More)
We consider passive airborne receivers that use backscattered signals from sources of opportunity transmitting fixed-frequency waveforms, which we refer to as Doppler Synthetic Aperture Hitchhiker (DSAH). We present a novel image formation method for DSAH. Our method first correlates the windowed signal obtained from one receiver with the windowed,(More)
We develop a new passive image formation method capable of exploiting information about multiple scattering in the environment, as well as statistics of the objects to be imaged, additive noise and clutter, using measurements from a sparse array of receivers that rely on illumination sources of opportunity. The array of receivers can be distributed(More)
Diffuse optical tomography (DOT) in the near infrared involves the reconstruction of spatially varying optical properties of a turbid medium from boundary measurements based on a forward model of photon propagation. Due to the nonlinear nature of DOT, high quality image reconstruction is a computationally demanding problem which requires repeated use of(More)
In this work, we present spatially resolved pharmacokinetic rate images of indocyanine green (ICG) obtained from three breast cancer patients using near infrared imaging methods. We used a two-compartment model, namely, plasma and extracellular extravascular (EES), to model ICG kinetics around the tumor region. We introduced extended Kalman filtering (EKF)(More)
— In this paper we present an analytic filtered-backpropagation inversion method for radar imaging when the transmitters and receivers are moving along independent flight paths. The flight paths are arbitrary, but assumed known. We assume a single-scattering model for the radar data, and we assume that the ground topography is known. We assume, in addition,(More)
We present a novel passive image formation method for moving targets using distributed apertures capable of exploiting information about multiple-scattering in the environment. We assume that the environment is illuminated by non-cooperative transmitters of opportunity with unknown location and unknown transmitted waveforms. We develop a passive measurement(More)
We present a unified theory for passive synthetic aperture imaging based on inverse scattering, estimation-detection theory and microlocal analysis. Passive synthetic aperture imaging uses sources of opportunity for illumination and moving receivers to measure scattered field. We consider passive airborne receivers that fly along arbitrary, but known,(More)