This paper proposes a method for determining the location of GSM mobile transmitters. The process discussed here estimates the location of a source without the use of multilateration or LOS techniques. A Multipath Characteristic Database (MCD) containing the multipath signatures for each possible transmitter location in an area of interest is populated via ray-tracing software simulations. The multipath characteristics of interest are Angle of Arrival (AOA), and Time Difference of Arrival (TDOA). An analysis of an eigenstructure Joint Angle and Delay Estimations (JADE) is presented, and the properties of the MCD are discussed. Since the proposed method utilizes a simulated multipath signature database the need for a priori soundings from the area of interest is eliminated, thus making this location estimation system ideal for use in hostile territories.

The error due to discretization in a method-ofmoments analysis of a parallel plate or metal-insulator-metal (MIM) capacitor is discussed. A technique related to Richardson extrapolation is used to develop a model for the error due to subsectional discretization. The results are for Galerkin's method using rooftop basis functions; however, the technique can be applied to any variational moment-method calculation. An expression is presented for the error in capacitance calculations, which is shown to hold for changes in geometry and dielectric constant. In addition, the expression for error is shown to be accurate for a wide range of meshing geometries. Surprisingly, the error model is not an upper bound, but rather is met nearly in equality for all geometries considered. Thus, the error may be simply subtracted from the calculated value for a more accurate result.

Indoor emitter localization is a topic of continued interest for improving wireless security as wireless technologies continue to become more advanced. Conventional methods have focused on the localization of devices relative to multi-sensor systems owing to ease of implementation with pre-existing infrastructures. This work, however, focuses on enhancing wireless security via non-cooperative emitter localization in scenarios where only a single receiver can be employed. A vector sensor is simulated and experimentally developed that extracts three-dimensional signal characteristics for room-based emitter localization and is compared to conventional methodologies such as Received Signal Strength (RSS), Time of Arrival (ToA), and Direction of Arrival (DoA). The proposed method generates time-frequency fingerprints and extracts features through dimensionality reduction. A second stage extracts spatial parameters consisting of Channel State Information (CSI) and DoAs that are analyzed using a Gaussian Mixture Model (GMM) to segregate fine-grained regions of interest within each room where the non-cooperative emitter resides. Blind channel equalization cascaded with a least squares channel estimate is used for acquiring the CSI, whereas the DoAs are obtained by unique trigonometric properties of the vector sensing antenna. The results demonstrate that a vector sensor can improve non-cooperative emitter localization and enhance wireless security in indoor environments.

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Carbon fiber composite (CFC) materials have been used for many structural applications for decades. Their electromagnetic properties are also of great interest and are being quantified by recent research. This research explores shielding effectiveness, antenna design, conductivity, reflection, and absorption properties. The work in this paper specifically characterizes the radar cross section (RCS) of CFC structures. Various CFC planar samples were created using a wet layup method and vacuum bagging techniques. These samples were then placed in an anechoic chamber and their RCS values were measured at normal incidence. These measured values were compared to those of aluminum samples made into the same shape as the CFC samples. All of the measurements were made over 7 -12 GHz frequency range. The RCS of the CFC samples show some interesting results. The fiber direction in the CFC samples had great influence on the RCS. Theories and reasoning for the results are presented and discussed.