Abstract: A spatially-distributed architecture (SDA) of antennas transmits respective uniquely coded signals. A first receiver having a known position in a coordinate system defined by the SDA receives reflected versions of the uniquely coded signals. A first processor receives the reflected versions of the uniquely coded signals and identifies a position of a non-cooperative object in the coordinate system. A platform with a platform receiver receives non-reflected versions of the uniquely coded signals. The platform determines a position of the platform in the coordinate system. In an example, the platform uses a self-determined position and a position of the non-cooperative object communicated from the SDA to navigate or guide the platform relative to the non-cooperative object. In another example, the platform uses a self-determined position and information from an alternative signal source in a second coordinate system to guide the platform. Guidance solutions may be generated in either coordinate system.

Abstract: A system includes a set of spatially separated transmit antenna elements (SSTAE) broadcasting uniquely identifiable waveforms, a set of spatially separated receive antenna elements (SSRAE) and at least one circuit assembly. The at least one circuit assembly is electrically coupled to the SSRAE, which provide respective electrical signals responsive to the uniquely identifiable waveforms. The electrical signals include at least one target signal and electromagnetic interference. The circuit assembly operates on the electrical signals to create a matched projection space parallel to a reference related to the at least one target signal and a second projection space that is orthogonal or nearly orthogonal to the matched projection space. The second projection space includes the electromagnetic interference but not the at least one target signal. The circuit assembly uses the second projection space and the matched projection space to separate the electromagnetic interference from the at least one target signal.

Abstract: A spatially-distributed architecture (SDA) of antennas transmits respective uniquely coded signals. A first receiver having a known position in a coordinate system defined by the SDA receives reflected versions of the uniquely coded signals. A first processor receives the reflected versions of the uniquely coded signals and identifies a position of a non-cooperative object in the coordinate system. A platform with a platform receiver receives non-reflected versions of the uniquely coded signals. The platform determines a position of the platform in the coordinate system. In an example, the platform uses a self-determined position and a position of the non-cooperative object communicated from the SDA to navigate or guide the platform relative to the non-cooperative object. In another example, the platform uses a self-determined position and information from an alternative signal source in a second coordinate system to guide the platform. Guidance solutions may be generated in either coordinate system.

Abstract: A spatially-distributed architecture (SDA) of antennas transmits a set of uniquely coded signals. A first receiver having a known position in a coordinate system defined by the SDA receives reflected versions of the uniquely coded signals. A first processor receives the reflected versions of the uniquely coded signals and identifies a position of a non-cooperative object in the coordinate system. A platform having a second receiver receives non-reflected versions of the uniquely coded signals. The platform determines a position of the platform in the coordinate system. In an example, the platform uses a self-determined position and a position of the non-cooperative object communicated from the SDA to navigate or guide the platform relative to the non-cooperative object. In another example, the platform uses a self-determined position and information from an alternative signal source in a second coordinate system to guide the platform after a coordinate conversion.

Abstract: An adaptive parameter for adjusting a threshold in a sensor system that provides a constant false alarm rate is disclosed. A projection space generator performs projection operations to create a matched projection space and first and second mismatched projection spaces such that each mismatched projection space is orthogonal or nearly orthogonal to the matched projection space. A mitigation engine receives the matched and first mismatched projection spaces and generates a set of weights from one of the first mismatched projection space or both of the matched and first mismatched projection spaces. A second mismatched projection space that is mismatched to both the matched and first mismatched projection spaces is provided to a clutter characterization engine that generates samples from the second mismatched projection space and the set of weights. The adaptive parameter is generated from the samples and is used as an input to a threshold adjuster in a target detector.

Abstract: A received signal that includes a target signal and an interference signal is sampled in space and time and then filtered into a matched-filtered signal and into a mis-matched-filtered signal, which is orthogonal to, or nearly orthogonal to, the matched-filtered signal The interference signal is present in both the matched-filtered signal and the mis-matched-filtered signal, whereas the target signal is present in only the matched-filtered signal. In the mis-matched-filtered signal, the interference signal is different from the matched-filtered signal in the temporal property, but is the same as the matched-filtered signal in the spatial property. After the matched-filtered signal and the mis-match-filtered signals have been obtained for the signals received by each antenna element of an array of antenna elements, they are processed to obtain a result vector, W, that is a representation of the target signal without the interference.

Abstract: Systems and methods are provided for mitigating natural and man-made interference through the use of one or more orthogonal, or nearly-orthogonal, projections of the received signal, which is assumed to be contaminated with interference, into one or more orthogonal projection spaces based on properties of the signal of interest. Once separated into orthogonal projection space(s), the system and method use information contained in the orthogonal projection space(s) to separate the signal of interest, or target signal, from the interference and to mitigate the interference.

Abstract: An adaptive parameter for adjusting a threshold in a sensor system that provides a constant false alarm rate is disclosed. A projection space generator performs projection operations to create a matched projection space and first and second mismatched projection spaces such that each mismatched projection space is orthogonal or nearly orthogonal to the matched projection space. A mitigator engine receives the matched and first mismatched projection spaces and generates a covariance matrix from the first mismatched projection space and an image space from the covariance matrix and the matched projection space. A second mismatched projection space that is mismatched to both the matched and first mismatched projection spaces is provided to a clutter characterization engine that generates samples from the second mismatched projection space and the covariance matrix. The adaptive parameter is generated from the samples and is used as an input to a threshold adjuster in a target detector.

Abstract: A system for providing a multi-mode, multi-static interferometer may include a transmitter array, a receiver array and a processor. The transmitter array includes at least a first transmitter and a second transmitter spatially separated from each other by a first known distance. The receiver array includes at least a first receiver and a second receiver spatially separated from each other by a second known distance. The receiver array is positioned to enable receipt of a return signal from transmissions provided by the transmitter array and reflecting off an object. The processor is configured to enable the transmitter array to generate uniquely coded signals and configured to distinguish, based on the uniquely coded signals, a first signal transmitted by the first transmitter from a second signal transmitted by the second transmitter in response to reception of a combined signal including reflected signals corresponding to at least the first and second signals by the receiver array.

Abstract: A received signal that includes a target signal and an interference signal is sampled in space and time and then filtered into a matched-filtered signal and into a mis-matched-filtered signal, which is orthogonal to, or nearly orthogonal to, the matched-filtered signal. The interference signal is present in both the matched-filtered signal and the mis-matched-filtered signal, whereas the target signal is present in only the matched-filtered signal. In the mis-matched-filtered signal, the interference signal is different from the matched-filtered signal in the temporal property, but is the same as the matched-filtered signal in the spatial property. After the matched-filtered signals and the mis-match-filtered signals have been obtained for the signals received by each antenna element of an array of antenna elements, they are processed to obtain a result vector, W, that is a representation of the target signal without the interference.

Abstract: Systems and methods are provided for mitigating natural and man-made interference through the use of one or more orthogonal, or nearly-orthogonal, projections of the received signal, which is assumed to be contaminated with interference, into one or more orthogonal projection spaces based on properties of the signal of interest. Once separated into orthogonal projection space(s), the system and method use information contained in the orthogonal projection space(s) to separate the signal of interest, or target signal, from the interference and to mitigate the interference.

Abstract: A system and method for predicting the probability of cloud-to-ground lightning strikes, ‘frequent’, more than 2 strikes per minute on average, cloud to ground lightning strikes, and/or ‘numerous’, more than 4 strikes per minute on average, through the use of polarimetric radar is presented. The data volume created by the polarimetric radar is processed to identify the type of hydrometeors in each range cell. For each vertical column, the maximum height of the graupel is compared to the lowest height of ice crystals in the volume. In the event that the lowest height of ice crystals is ambiguous, the height of the temperature where ice crystals form, ?10° C., may be substituted for the lowest height of the ice crystals. Probability density functions are applied to the height difference to determine the probability of cloud to ground lightning within the column. Lightning probability product data are displayed on a visualization system in a georeferenced manner providing georeferenced lightning warnings.