Abstract:
Devices and methods of providing response pulses in response to threat pulses are general described. The threat pulses are detected, identified and validity determined using reprogrammable firmware. Threat pulses are extracted from memory and the amplitude, frequency, phase, length and timing modified to generate a coherent set of superposed response pulses in response to the threat pulses. The modifications are calculated in situ using parameterization, rather than being based on tables. Multiple response pulses in response to different threat pulses are simultaneously generated, combined and transmitted in a single channel. Partial pulse capability and the capability to create a weighted and modulated composition of multiple response pulses is provided.
Abstract:
A method and system for data conversion includes an analog noise generator to generate a random, non-deterministic, analog noise signal. An adder adds the analog noise signal to an analog RF signal to produce a dithered analog signal. A first quantizer converts the analog noise signal to digital to produce a digital noise signal. A second quantizer converts the dithered analog signal to a digital equivalent signal. A digital dither adjustment module removes amplitude measurements of the digital noise signal from the digital equivalent signal to obtain a linearized digital representation of the analog RF signal.
Abstract:
Methods and systems are disclosed for compensating for image motion induced by a relative motion between an imaging platform and a scene. During an exposure period, frames of the scene may be captured respectively in multiple spectral bands, where one of the spectral bands has a lower light level than the first spectral band, and contemporaneous frames include a nearly identical induced image motion. Image eigenfunctions are utilized to estimate the induced image motion from the higher SNR spectral band, and compensate in each of the multiple bands.
Abstract:
A system for tracking targets. A sequence of sensor observations is processed with two thresholds, including a first threshold, and a second threshold, higher than the first threshold. Signals that exceed the first threshold are identified as low-confidence target detections and stored for possible future use. When a signal exceeds the higher second threshold, it is identified as a high-confidence detection, and one or more candidate tracks are formed, including the high-confidence detection and one or more low-confidence detections from within a neighborhood of the high-confidence detection.
Abstract:
Technology for determining a geographical location of a ground receiver is disclosed. A plurality of radio frequency (RF) signals from a plurality of RF signal carriers may be received at the ground receiver. The plurality of RF signal carriers may include satellites operated by a foreign entity or non-global positioning system (non-GPS) satellites. The ground receiver may measure a Doppler shift associated with each of the plurality of RF signals. The geographical location of the ground receiver may be determined in X, Y and Z coordinates based in part on the Doppler shift associated with each of the plurality of RF signals.
Abstract:
A method includes generating a sampling signal having a non-uniform sampling interval and sampling a received signal with an analog-to-digital converter (ADC) using the sampling signal. The method also includes mapping the sampled received signal onto a frequency grid of sinusoids, where each sinusoid has a signal amplitude and a signal phase. The method further includes estimating the signal amplitude and the signal phase for each sinusoid in the frequency grid. In addition, the method includes computing an average background power level and detecting signals with power higher than the average background power level. The non-uniform sampling interval varies predictably.
Abstract:
Methods and systems are provided for estimating background spectral content in a hyperspectral imaging (HSI) scene. A HSI processor computes a scene covariance matrix for each of a plurality of sparsely sampled pixel sets, identifies and removes the spectral content of contaminating pixels from the covariance matrices, and checks the consistency among the plurality of decontaminated covariance matrices, iteratively re-sampling and re-computing said matrices until an acceptable consistency is achieved, and then computes a final decontaminated covariance matrix representative of the background spectral content of the scene. Alternate approaches to pixel sampling, and/or using fewer spectral dimensions than are available for the pixels are presented.
Abstract:
Method and apparatus for generating channelized hardware-independent waveforms include: generating metadata associated with a waveform, the metadata including a frequency list, a phase list and amplitude information, wherein the metadata is generated independent of a number of channels; interpreting the metadata to generate channel select, frequency, phase and amplitude parameters; providing the frequency, phase and amplitude parameters to a direct digital synthesizer (DDS) to generate a digital signal; providing the channel select parameter to a channel selector to generate a plurality of channelized waveforms from the generated digital signal; and transmitting the plurality of channelized waveforms over a plurality of communication channels.
Abstract:
Technology for determining a geographical location of a ground receiver is disclosed. A plurality of radio frequency (RF) signals from a plurality of RF signal carriers may be received at the ground receiver. The plurality of RF signal carriers may include satellites operated by a foreign entity or non-global positioning system (non-GPS) satellites. The ground receiver may measure a Doppler shift associated with each of the plurality of RF signals. The geographical location of the ground receiver may be determined in X, Y and Z coordinates based in part on the Doppler shift associated with each of the plurality of RF signals.