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Full-Text Articles in Engineering
Clustered Hyperspectral Target Detection, Sean Onufer Stalley
Clustered Hyperspectral Target Detection, Sean Onufer Stalley
Dissertations and Theses
Aerial target detection is often used to search for relatively small things over large areas of land. Depending on the size and signature of the target, detection can be a very easy or very difficult task. By capturing images with several hundred color channels, hyperspectral sensors provide a new way of looking at this task, both literally and figuratively. Hyperspectral sensors can be used in many aerial target detection tasks such as identifying unhealthy trees in a forest, searching for minerals at a mining site, or finding the sources of chemical leaks at a factory. The high spectral resolution of …
A Simplified Accuracy Enhancement To The Saleh Am/Am Modeling And Linearization Of Solid-State Rf Power Amplifiers, Haider Al-Kanan, Fu Li
A Simplified Accuracy Enhancement To The Saleh Am/Am Modeling And Linearization Of Solid-State Rf Power Amplifiers, Haider Al-Kanan, Fu Li
Electrical and Computer Engineering Faculty Publications and Presentations
The Saleh behavioral model exhibits high prediction accuracy for nonlinearity of traveling-wave tube power amplifiers (TWT-PAs). However, the accuracy of the Saleh model degrades when modeling solid-state power amplifiers (SSPAs) technology. In addition, the polynomial expansion of the Saleh model consists of only odd-order terms as analyzed in this work. This paper proposes a novel model accuracy enhancement for the Saleh amplitude-to-amplitude (AM/AM) model when applied to radio frequency (RF) SSPAs. The proposed model enhancement accounts for the second-order intermodulation distortion, which is an important nonlinearity challenge in wideband wireless communications. The proposed static AM/AM model is a three-parameter rational …
Inversion Of Head Waves In Ocean Acoustic Ambient Noise, Jie Li, Peter Gerstoft, Martin Siderius, Jun Fan
Inversion Of Head Waves In Ocean Acoustic Ambient Noise, Jie Li, Peter Gerstoft, Martin Siderius, Jun Fan
Electrical and Computer Engineering Faculty Publications and Presentations
The virtual head wave is produced through cross-correlation processing of signals containing the real, acoustic head wave. The virtual head wave has the same phase speed as the head wave, but the travel time is offset, thus the term virtual. The virtual head wave, like the real head wave, propagates in a direction corresponding to the seabed critical angle. The virtual head wave travel time varies with array depth and water column depth. However, in a refracting environment, the travel time is also dependent on the depth-dependent sound speed profile. Previously, the virtual head wave was shown as observable from …