Abstract: A system, method and apparatus is provided for calculating the position of a single receiver by receiving a signal from an emitter. Either the receiver or the emitter may be stationary relative to the surface of the Earth. The invention may use a particle filter to optimize the efficiency of the position calculation. The invention may further utilize a particle filter to estimate the frequency drift and bias of the emitter and/or receiver, and use the estimated frequency drift to improve the position calculation. In one embodiment, the invention may be used to calculate the position of a single GPS receiver given the position of, and a transmission from, a single GPS satellite.

Abstract: The described invention allows for rapid geolocation of one or more RF emitters using a single moving collection platform. Inaccuracies of conventional frequency of arrival (FOA) geolocation methods are overcome by solving simultaneously for emitter location and a potential emitter drift associated with an observed emitter frequency. Certain embodiments may utilize particle filtering algorithms to recursively update multimodal state densities that are typical of solutions involving both unknown emitter location and nonstationary emitter carrier drift. Moreover, certain properties of particle filters may be exploited to provide a geolocation solution given a complex multimodal state space composed of emitter location and a non-stationary emitter frequency required for FOA.

Abstract: A display system for creating a full-color projected image. Light from a white light source passes through a color modulator (106). The color modulator (106) is a stack of at least two dielectric layers exposed to an electric field. The applied electric field operates to change the index of refraction of the dielectric material enough to cause the stack of dielectric layers to selectively reflect or transmit various wavelength bands. By changing the electric field, the color modulator (106) provides a series of three primary color light beams that are modulated by a spatial light modulator (112). A controller (128) controls the operation of the spatial light modulator (112) to form an image bearing beam of primary colored light. The image bearing beam of light is focused onto an image plane by a projection optics (124).

Abstract: A digital graphic equalizer uses a predetermined number of equalizing bands each having a different center frequency, and the center frequencies span a predetermined audio bandwidth. For each equalizing band a minimum set of filters is provided. The filters have a predetermined linear uniform spacing between the gain of successive filters.