Bae Systems Information and Electronic Systems Integration Inc.

Wisterium Development LLC

Allan M Kabel

Keith A Struckman

Thomas R Vaccaro

Techniques are disclosed for partial band signal reconstruction. A partial band signal reconstruction circuit includes a zero generator, an analysis filter, and a synthesis filter. The zero generator is configured to generate a zero-value channel (i.e., a signal of all zeros). The analysis filter is configured to convert a wideband time-domain signal into K narrow-band channels, and to select at least R of the K frequency-domain subchannels for synthesis. The synthesis filter is configured to receive the at least R subchannels from the analysis filter and the zero or more zero-value channels from the zero generator and convert the at least R subchannels and the zero-value channels (a total of P channels) into a time-domain signal. The values of K and P are related by a constraint that constrains one or more parameters of the analysis filter and the synthesis filter.

Partial band signal reconstruction using arbitrary numbers of synthesis channels

A method and system for Kalman-Filtering in geolocation is provided. One aspect of the disclosure provides using an extreme geo program/method to converge on the location of an emitter, using a correlation function inherent in a Correlation Interferometry Geolocation (CIGL) program, and using Kalman filtering to find a peak correlation surface for an array.

Kalman filtered correlation interferometry geolocation

A radio geolocation system is described in which a plurality of moving platforms such as aircraft concurrently receive a signal from a remote transmitter and the geolocation of the transmitter is determined. At each platform every thirty seconds a plurality of samples of the received signal are taken over a one second period. The samples are digitized and a time and GPS location stamp are added to each sample. The digitized samples with time and location stamps from all platforms are transmitted to a central location and stored in covariance matrices, one matrix per one second sample period. The signal samples in each matrix are processed utilizing a unique algorithm to generate a data set which defines a correlation surface. The data from a plurality of data sets are summed together on a point by point basis and normalized to yield a summation data set which defines a summation correlation surface. The summation correlation surface has a well defined peak that defines the geolocation of the remote transmitter.

Multiplatform TDOA correlation interferometer geolocation

A channelized filter design for partial band reconstruction having high dynamic range requirements. The analysis filter and synthesis filter constraints permit high performance signal detection with an alias free signal recombination capability for signals that span multiple frequency bins. The filter bank allows the use of a single wideband asset to provide for data channelized for detection processing with the ability to recombine one or more adjacent frequency bins into a wider bandwidth baseband time domain data stream suitable for exploitation processing. Use of an efficient partial band reconstruction mechanism allows signal reconstruction using only the frequency subchannels that pertain to the signal of interest that is to be copied. The filter design mechanism separates the specification of the analysis filter to support signal detection in environments of high dynamic range. The signal reconstruction (synthesis) filter uses fewer bins and allows a higher order filter.

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Hollis, NH, United States of America

Allan M Kabel