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Full-Text Articles in Engineering
Signal Processing Strategies That Improve Performance And Understanding Of The Quantitative Ultrasound Spectral Fit Algorithm, Timothy A. Bigelow, William D. O'Brien
Signal Processing Strategies That Improve Performance And Understanding Of The Quantitative Ultrasound Spectral Fit Algorithm, Timothy A. Bigelow, William D. O'Brien
Timothy A. Bigelow
Quantifying the size of the tissue microstructure using the backscattered power spectrum has had limited success due to frequency-dependent attenuation along the propagation path, thus masking the frequency dependence of the scatterer size. Previously, the SPECTRAL FIT algorithm was developed to solve for total attenuation and scatterer size simultaneously [Bigelow et al., J. Acoust. Soc. Am. 117, 1431-1439 (2005)]. Herein, the outcomes from signal processing strategies on the SPECTRAL FIT algorithm are investigated. The signal processing methods can be grouped into two categories, viz., methods that improve the performance of the algorithm and methods that provide insight. The methods that …
The Navigation Potential Of Signals Of Opportunity-Based Time Difference Of Arrival Measurements, Kenneth A. Fisher
The Navigation Potential Of Signals Of Opportunity-Based Time Difference Of Arrival Measurements, Kenneth A. Fisher
Theses and Dissertations
This research introduces the concept of navigation potential, NP, to quantify the intrinsic ability to navigate using a given signal. NP theory is a new, information theory-like concept that provides a theoretical performance limit on estimating navigation parameters from a received signal that is modeled through a stochastic mapping of the transmitted signal and measurement noise. NP theory is applied to SOP-based TDOA systems in general as well as for the Gaussian case. Furthermore, the NP is found for a received signal consisting of the transmitted signal, multiple delayed and attenuated replicas of the transmitted signal, and measurement noise. Multipath-based …
Digital Calculation Of Frequency Of Periodical Signal (Sinusoidal And Triangular, Tarak Benslimane, Boukhemis Chetate
Digital Calculation Of Frequency Of Periodical Signal (Sinusoidal And Triangular, Tarak Benslimane, Boukhemis Chetate
Boukhemis Chetate
– In This paper, a method of digital calculation of frequency of periodical signal (sinusoidal, triangular and square signals) is proposed. This method is based on calculation of time between two successive peaks of the rectified signal which constitutes it’s half period. This method allows the measurement of AC current and voltage of AC electrical network. To apply this method, it is necessary to have current and voltage sensors, analogue/ digital converter (ADC) and a processor. A software C++ based program is developed which can be implemented using appropriate processor. In the end are presented the digital simulation results.
Depth-Shifting Of Shallow Water Guide Source Observations, Lisa M. Zurk, Brian H. Tracey
Depth-Shifting Of Shallow Water Guide Source Observations, Lisa M. Zurk, Brian H. Tracey
Electrical and Computer Engineering Faculty Publications and Presentations
In theory, matched field processing offers the significant benefit of higher signal gains and increased localization capability. However, this has not been robustly observed in practice because of inherent uncertainties about details of the shallow water propagation environments which limit the prediction of the channel response. The use of guide sources to directly measure the transfer function between source and receiver arrays has been proposed as a means for reducing mismatch. However, the guide source measurement only provides a measured transfer function at the guide source location. In this paper a method of depth-shifting guide source observations is proposed, making …