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An algorithm for detection of continuous-wave noise jamming in two-dimensional surveillance radar is proposed. The algorithm is highly immune to strong interfering spikes due to using censored video integration of range noise samples collected during dwell time for each azimuth resolution cell. To detect noise jamming the algorithm applies order statistics CFAR to a sequence of azimuthal samples resulted...
Conventional two-dimensional (2-D) autofocus algorithms blindly estimate the phase error in the sense that they do not take advantages of the known structure of the phase error. As such, they do not achieve accurate estimation of the 2-D phase error due to lack of data redundancy. In this paper, we propose a novel 2-D autofocus algorithm that exploits the phase structure information, which is known...
The inherent amplitude modulation of orthogonal frequency division multiplexing (OFDM) has limited its use in radar due to transmitter-induced distortion. Specifically, there is a necessary trade-off between reduced SNR caused by power back-off to accommodate these AM effects and the waveform distortion that occurs when driving the amplifier closer to saturation. Here a method is developed to design...
Wall ringing and reverberation pose a challenging problem for through-the-wall radar image formation algorithms. We propose a novel method based on compressive sensing (CS) that enables high reconstruction quality combined with efficient data collection. A joint wall reverberation and target model is developed and the reconstructed scene is obtained based on a group sparse CS approach. Thus, the wall...
This paper describes the X-band dual polarization phased array radar developed at the University of Massachusetts. The high level system architecture is presented and an in-field calibration procedure is developed.
Multiple-input multiple-output (MIMO) radar using one-dimensional transmit arrays has been thoroughly investigated in the literature. In this paper, we consider the MIMO radar problem in the context of two-dimensional (2D) transmit arrays. In particular, we address the problem of transmit beamforming design using 2D arrays with symmetrically missing elements. This situation is encountered in practice...
A photonic analog-to-digital converter exploiting a sample time-interleaving approach is presented, showing more than 7 effective bits for input signals up to 40GHz and bandwidth up to 200MHz. The effective 1-to-4 optical sample parallelization scheme does not contaminate the low sampling jitter with limited crosstalk. A real-time digital post-processing is also added to increase the ADC linearity...
Bistatic Inverse Synthetic Aperture Radar has recently gained interest as bistatic and multistatic radar systems are becoming increasingly popular. A theoretical foundation has been laid that introduces the concept of Bistatically Equivalent Monostatic (BEM) configuration, which allows approximating a bistatic geometry with a monostatic one. This greatly simplifies not only the geometrical understanding...
In this paper we report on initial results into Doppler imaging, a technique by which both down and cross-range resolution are obtained with low bandwidth waveforms. Conventional radar imaging utilizes aperture synthesis to obtain cross-range resolution and relies on wideband waveforms for the downrange resolution. More recently, tomography has been proposed an alternative able to generate high-resolution...
In this paper, a pulse compression with complex valued window, termed PCX, is proposed to achieve low range sidelobe, low mismatch loss and small broadening factor simultaneously. By modeling distributed sidelobe clutter with steering vectors, a complex-valued window minimizing the distributed clutter power is derived. Proposed PCX shows superior performance against Taylor windowed pulse compression...
Radar can be used to detect human heartbeats. This makes radar a potential alternative to today's heartbeat monitoring techniques in medicine. In this paper, two antennas were located on the chest to monitor the heart activity. Simultaneous with the radar measurements, the Electrocardiogram (ECG) and blood pressure were measured. Details of the heart activity, such as opening and closing of heart...
Improvised explosive devices (IEDs) pose a significant hazard to allied forces. Effective countermeasures should exploit components that are commonly found in IEDs. This paper presents the computer modeling and measurement of the monostatic radar cross section (RCS) of one of these components, the electric hot-wire detonator. Results indicate that the common mode associated with the detonator's casing...
The eSPACE project (emergency Spatial Pre-SCAT for Arctic Coastal Ecosystems; SCAT: Shoreline Cleanup and Assessment Technique) is focused on developing capacity to enhance our state of preparedness for emergencies in the event of an oil spill in Canada's North. Baseline coastal information is required for operational prioritization, coordination of on-site spill response activities and wildlife management...
The Canadian Department of National Defence (DND) is cleaning up and remediating environmental hazards at former Distant Early Warning (DEW) Line sites located across the Canadian Arctic. The DEW Line Clean-Up proof of concept project is underway, to determine if space-based Synthetic Aperture Radar (SAR) data can be used for landfill monitoring at these DEW Line sites. Interferometric time series...
Possible differences between boresight and off-boresight emissions of phased array radar systems can impact a radar system's performance. This could result in a distorted transmitted radar waveform. In order to understand the significance of this distortion on a radar system, a simulation study was completed for a notional 3.5 GHz radar having both a continuous wave pulsed waveform and a linear FM...
Localization of unknown radio frequency (RF) transmitters is useful for a variety of applications such as clutter cancelation, cognitive radio, cognitive radar, bistatic and multistatic radar. Current methods for localization include triangulation through phase difference, amplitude and time of arrival measurements. However, all these methods have their drawbacks. The received signal strength (RSS)...
Sparsity-based STAP algorithms exploit the sparsity that the clutter spectrum only occupies a small number of spatio-temporal bins in the whole spatio-temporal plane, and provide an effective approach to suppress the clutter especially in very short snapshots. However, existing sparsity-based STAP algorithms either require high computational complexity, or have complex parameter settings, which results...
A method for 3D reconstruction of moving targets based on dual interferometric Inverse Synthetic Aperture Radar (ISAR) is presented in this paper. The interferometric phases measured from two orthogonal baselines are used to jointly estimate the effective rotation vector and the scattering centre heights. The scattering centre extraction from the ISAR image is performed by applying a multichannel...
Fast Polarization MUSIC is an algorithm which can utilize the advantage of the signals polarization state to estimate their directions. Its capacity in resolving close signals is considerably enhanced, with acceptable computation complexity. In this paper, analysis of this algorithm's performance in estimation precision, resolution of close signals and computation complexity are presented. Relating...
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