ToA Ranging and Layer Thickness Computation in Nonhomogeneous Media

Entropy-Based TOA Estimation and SVM-Based Ranging Error Mitigation in UWB Ranging Systems

The major challenges for Ultra-wide Band (UWB) indoor ranging systems are the dense multipath and non-line-of-sight (NLOS) problems of the indoor environment. To precisely estimate the time of arrival (TOA) of the first path (FP) in such a poor environment, a novel approach of entropy-based TOA estimation and support vector machine (SVM) regression-based ranging error mitigation is proposed in ...

Internal Forces in Piles “Under External Forces and Earthquake in Homogeneous and Nonhomogeneous Media”

WLAN TOA Ranging and GPS Hybrid System for Indoor Navigation

Position errors for a GPS standalone solution can exceed 200 meters in indoor environments due to limited satellite availability, weak signals and multipath. Therefore hybrid positioning methods have been developed integrating other signals and sensors including pseudolites, ultrawideband, cell ID and WLAN fingerprinting with GPS to aid navigation in indoor environments. Service providers using...

Internal Forces in Piles “Under External Forces and Earthquake in Homogeneous and Nonhomogeneous Media”

Inverse Source Problem in Nonhomogeneous Background Media

The scalar wave inverse source problem (ISP) of determining an unknown radiating source from knowledge of the field it generates outside its region of localization is investigated for the case in which the source is embedded in a non-homogeneous medium with known index of refraction profile n(r). It is shown that the solution to the ISP having minimum energy (socalled minimum energy source) can...