Abstract: Correlation interferometry direction finding (CIDF) processes that significantly improve processing time and cut memory requirements relative to the current memory requirements are provided herein. The presently disclosed processes further may utilize only the real portion of the correlation coefficient of the RF signal to further increase processing speed and decrease memory requirements while simultaneously improving direction finding accuracy and reducing the number of wild bearings reported.

Abstract: Correlation interferometry direction finding (CIDF) processes that significantly improve processing time and cut memory requirements relative to the current memory requirements are provided herein. The presently disclosed processes further may utilize only the real portion of the correlation coefficient of the RF signal to further increase processing speed and decrease memory requirements while simultaneously improving direction finding accuracy and reducing the number of wild bearings reported.

Abstract: A system and method that can determine the direction of origin within 360 degrees around an antenna array for an emitted signal with a high degree of accuracy, even when the array is installed in a corrupted or “unclean” environment. Further, the provided system and method can provide a more accurate indication of direction despite polarization of the detected signal. Finally, the provided system and method can provide accurate results from phase measurements, amplitude measurements, or both phase and amplitude measurements, from an emitted signal where a phase network can be used to tailor the amplitude and phase variations versus spatial angle to best match the receiver measurement accuracies.

Abstract: An antenna receiver has antenna elements that are arranged in an array and spaced apart from each other at a distance greater than one-half wavelength of the highest operating frequency of a signal that is to be detected by the antenna receiver. The antenna receiver has geolocation logic that uses the inter-element phase difference measurements to obtain a location of the signal source. The change in the inter-element phase differences enables the elements to be spaced apart at great distances, which is beneficial for the physical construction of the platform, as the elements may be easily placed at convenient locations for conformal aerodynamic properties.

Abstract: A process of screening direction finding solutions to reduce the number of valid direction finding solution rejections while maintaining an acceptable level of wild bearings being reported utilizing the proximity of the correlation values of the highest correlation and second highest correlation given a correlation pattern of a detected signal of unknown origin.

Abstract: A direction finding system and method to utilize synthetic apertures within a single short pulse transmission to extrapolate additional data relating to the signal to thereby increase the accuracy of the direction finding results given by a single short pulse is provided. The direction finding system may further exploit the movement of a platform to create the synthetic apertures within the signal data.

Abstract: A process of screening direction finding solutions to reduce the number of valid direction finding solution rejections while maintaining an acceptable level of wild bearings being reported utilizing the proximity of the correlation values of the highest correlation and second highest correlation given a correlation pattern of a detected signal of unknown origin.

Abstract: An antenna receiver has antenna elements that are arranged in an array and spaced apart from each other at a distance greater than one-half wavelength of the highest operating frequency of a signal that is to be detected by the antenna receiver. The antenna receiver has geolocation logic that uses the inter-element phase difference measurements to obtain a location of the signal source. The change in the inter-element phase differences enables the elements to be spaced apart at great distances, which is beneficial for the physical construction of the platform, as the elements may be easily placed at convenient locations for conformal aerodynamic properties.

Abstract: A method for improving target location accuracy in direction finding systems is disclosed. A target search region is identified based on a set of received signals, and the target search region is projected onto the earth's surface. An initial search grid, which is smaller than the target search region, is placed within the target search region. Next, the initial search grid is expanded to a full search grid by using an optimum number of virtual grid points in order to cover the entire target search region. The correlation coefficients at the virtual grid points between the estimated phases of emitted signals and the estimated phases of the received signals are then calculated. A target is designated as being at a location associated with the highest correlation coefficient. At this point, a new travel path can be initiated to engage or avoid the target.

Abstract: A method for improving target location accuracy in direction finding systems is disclosed. A target search region is identified based on a set of received signals, and the target search region is projected onto the earth's surface. An initial search grid, which is smaller than the target search region, is placed within the target search region. Next, the initial search grid is expanded to a full search grid by using an optimum number of virtual grid points in order to cover the entire target search region. The correlation coefficients at the virtual grid points between the estimated phases of emitted signals and the estimated phases of the received signals are then calculated. A target is designated as being at a location associated with the highest correlation coefficient. At this point, a new travel path can be initiated to engage or avoid the target.

Abstract: A method for improving direction finding and geolocation error estimation in direction finding and geolocation systems is disclosed. The corresponding phases of the received signals are determined. After an initial target estimation point of the received signals has been identified, the initial target estimation point is projected onto the earth's surface. A search grid having multiple grid points is then overlaid on the projected initial target estimation point, surrounding the projected initial target estimation point. The phase of signals emitting from a theoretical emitter located at each of the grid points of the search grid is estimated. Correlation coefficients between the estimated phases of the emitting signals and the determined phases of the received signals are determined. An error ellipse can be generated around one of the grid points having the highest correlation coefficient, and a source emitter is likely to be located within the error ellipse.

Abstract: A method for improving direction finding and geolocation error estimation in direction finding and geolocation systems is disclosed. The corresponding phases of the received signals are determined. After an initial target estimation point of the received signals has been identified, the initial target estimation point is projected onto the earth's surface. A search grid having multiple grid points is then overlaid on the projected initial target estimation point, surrounding the projected initial target estimation point. The phase of signals emitting from a theoretical emitter located at each of the grid points of the search grid is estimated. Correlation coefficients between the estimated phases of the emitting signals and the determined phases of the received signals are determined. An error ellipse can be generated around one of the grid points having the highest correlation coefficient, and a source emitter is likely to be located within the error ellipse.

Abstract: A communications system including an antenna array and electronics assembly that may be mounted on and in a vehicle. The communication system may generally comprise an external subassembly that is mounted on an exterior surface of the vehicle, and an internal subassembly that is located within the vehicle, the external and internal subassemblies being communicatively coupled to one another. The external subassembly may comprise the antenna array as well as mounting equipment and steering actuators to move the antenna array in azimuth, elevation and polarization (for example, to track a satellite or other signal source). The internal subassembly may comprise most of the electronics associated with the communication system.

Abstract: A communication system including a plurality of horn antennas, a waveguide feed network, and a converter unit coupled to the plurality of horn antennas is disclosed. The waveguide feed network is coupled to each horn antenna, splits an information signal into a first component signal having a first polarization and a second component signal having a second polarization and provides a first summed component signal at a first feed port and a second summed component signal at a second feed port. The converter unit receives the first summed component signal and the second summed component signal and compensates for polarization skew between the antenna array and a source.

Abstract: A communication system including a plurality of horn antennas, a waveguide feed network, and a converter unit coupled to the plurality of horn antennas is disclosed. The waveguide feed network is coupled to each horn antenna, splits an information signal into a first component signal having a first polarization and a second component signal having a second polarization and provides a first summed component signal at a first feed port and a second summed component signal at a second feed port. The converter unit receives the first summed component signal and the second summed component signal and compensates for polarization skew between the antenna array and a source.

Abstract: A communications system including an antenna array and electronics assembly that may be mounted on and in a vehicle. The communication system may generally comprise an external subassembly that is mounted on an exterior surface of the vehicle, and an internal subassembly that is located within the vehicle, the external and internal subassemblies being communicatively coupled to one another. The external subassembly may comprise the antenna array as well as mounting equipment and steering actuators to move the antenna array in azimuth, elevation and polarization (for example, to track a satellite or other signal source). The internal subassembly may comprise most of the electronics associated with the communication system.