Abstract: A method comprises: obtaining a GPS measurement; obtaining a first IMU measurement; obtaining a second IMU measurement; applying a first particle filter to the GPS measurement and the first IMU measurement to obtain a first position solution; applying a second particle filter to the GPS measurement and the second IMU measurement to obtain a second position solution; calculating a first sensor weight of the first position solution based on a likelihood function; calculating a second sensor weight of the second position solution based on the likelihood function; resampling the first position solution based on the first sensor weight to obtain a first resampled position solution; resampling the second position solution based on the second sensor weight to obtain a second resampled position solution; and calculating a final position estimate based on the GPS measurement, the first resampled position solution, and the second resampled position solution.

Abstract: A method comprises: obtaining a GPS measurement; obtaining a first IMU measurement; obtaining a second IMU measurement; applying a first particle filter to the GPS measurement and the first IMU measurement to obtain a first position solution; applying a second particle filter to the GPS measurement and the second IMU measurement to obtain a second position solution; calculating a first sensor weight of the first position solution based on a likelihood function; calculating a second sensor weight of the second position solution based on the likelihood function; resampling the first position solution based on the first sensor weight to obtain a first resampled position solution; resampling the second position solution based on the second sensor weight to obtain a second resampled position solution; and calculating a final position estimate based on the GPS measurement, the first resampled position solution, and the second resampled position solution.

Abstract: A delta-sigma modulator (DSM) includes: a first summation circuit coupled to an input signal for subtracting an error feedback signal from the input signal; a tunable signal transfer function coupled to the first summation circuit for setting a desired pole in a frequency response of the DSM; a second summation circuit coupled to the tunable signal transfer function for adding a noise transfer function to an output of the tunable signal transfer function; and a quantizer coupled to the second summation circuit for quantizing an output of the second summation circuit to generate an output of the DSM. The output of the DSM is used as feedback to the first summation circuit as the error feedback signal, and the tunable signal transfer function is dynamically tuned to allow selecting and tuning a center frequency and a bandwidth of the DSM.

Abstract: An ultrasonic communication system comprising an enclosure, a first module and a second module is described. The enclosure has an internal surface, an external surface, and defines at least one metal channel. The first module comprises an ultrasonic transceiver disposed within the enclosure. The first module is positioned on the internal surface of the enclosure and is capable of transmitting and/or receiving modulated ultrasonic waves via the metal channel. The second module is positioned on the external surface of the enclosure and is adapted to transmit and/or receive modulated ultrasonic waves from the first module via the metal channel.

Abstract: A synthetic aperture radar imaging method that combines each radar return pulse with a sinusoid to reduce the radar return pulses to a baseband frequency and deskew each radar return pulse. It includes determining a maximum likelihood estimate (MLE) of residual motion parameters for a dominant scatterer on the ground relative to the airborne radar and correcting for errors in inertial navigation system measurements based on the MLE residual motion parameters. It includes convolving each radar return pulse with its corresponding radar transmission pulse to generate a range compressed image for each radar return pulse and generating a sub-band range profile image for each radar return pulse and its corresponding radar transmission pulse based on the corresponding range compressed image that has been corrected for residual motion. Performing bandwidth extrapolation on each sub-band and subsequently combining the three bands to produce an enhanced resolution image without grating lobes.

Abstract: The disclosed approach provides a low-cost approach by employing a single channel receiver for a direction-finding missile, rather than a conventional four-channel system. It employs interferometry techniques. The proposed approach leverages orthogonal waveforms and pseudorandom noise (PN) codes. This is a low-cost approach for a single channel direction finding system by leveraging orthogonal waveforms and interferometric techniques.

Abstract: The disclosed approach provides a low-cost approach by employing a single channel receiver for a direction-finding missile, rather than a conventional four-channel system. It employs interferometry techniques. The proposed approach leverages orthogonal waveforms and pseudorandom noise (PN) codes. This is a low-cost approach for a single channel direction finding system by leveraging orthogonal waveforms and interferometric techniques.