Abstract: High precision radio frequency direction finding systems are described that can determine an angle-of-arrival and geo-location of a RF emitter with respect to a mobile platform. A radio frequency direction finding (RFDF) system for determining a position of a RF emitter with respect to a mobile platform can include an angle-of-azimuth (AoA) system configured to determine an azimuth of a RF emitter with respect to the mobile platform; an attitude measurement system configured to measure the attitude of the mobile platform; a geo-location system configured to calculate the geo-location of the RF emitter; and a processor system configured to calculate a position of the RF emitter.

Abstract: High precision radio frequency direction finding systems are described that can determine an angle-of-arrival and geo-location of a RF emitter with respect to a mobile platform. A radio frequency direction finding (RFDF) system for determining a position of a RF emitter with respect to a mobile platform can include an angle-of-azimuth (AoA) system configured to determine an azimuth of a RF emitter with respect to the mobile platform; an attitude measurement system configured to measure the attitude of the mobile platform; a geo-location system configured to calculate the geo-location of the RF emitter; and a processor system configured to calculate a position of the RF emitter.

Abstract: The invention is a pylon for supporting a model above a ground plane for radar cross-section testing using a radar providing a specific frequency range and power distribution above the ground plane. In detail, the pylon comprises a column made of a low dielectric constant foam material having a base end for mounting on the ground plane, a model mounting top end and a generally circular cross-section. The column has an abrupt change in diameter at a point between the ends forming a step and dividing the column into upper and lower tapered portions with each of the portions having a specific diameter range. The step is located at a point on the column such that the power is evenly split between the upper and lower portions and the specific diameter ranges of the portions are selected to maintain a 180-degree phase change in the return signal from each of the portions reducing the RCS of the pylon.

Abstract: A broadband multi-element antenna is presented. The antenna comprises a monopole centrally disposed within a cavity of the body, and a plurality of antenna elements disposed at ninety degree increments about the periphery of the cavity. A plurality of isolation traps are connected between selected pairs of the antenna elements. The isolation traps are half-wavelength transmission lines which permit excitation of the respective plurality of elements by input signals which are of equal amplitude and 180.degree. out-of-phase but are short circuits between the respective pairs for in phase signals parasitically induced from the monopole. Additionally, switching traps are connected to respective ones of the antenna elements. The switching traps comprise quarter-wave transmission lines which are switchable to ground and selectively provide a short circuit of signals at the respective ones of the elements for changing the radiation pattern of the antenna.