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Foliage Penetration Radar has been widely studied for detection and characterization of objects under dense foliage. The radar performance for detecting objects under foliage has generally been optimum in the VHF and UHF bands, where the spectrum is already dense with other RF communications applications. When the forest density is low, L-band is an alternate choice for area surveillance. The geographic...
This paper describes a novel approach to estimate two fundamental gait frequencies from a dismount observed by a radar that collects short dwells widely separated in time while it maintains wide area surveillance. For each dwell, range-Doppler images or chips are generated, and range versus range-rate maps are formed from few coherent processing intervals (CPIs) to obtain a spectrogram snapshot. The...
In this paper, a deep learning approach is proposed for target recognition based on high range resolution profiles (HRRPs) in multistatic radar systems. The proposed deep learning approach employs deep convolutional neural networks to automatically extract features from the HRRPs. In a multistatic radar system the target can be observed from multiple aspect angles simultaneously which improves the...
In this work we propose the GLRT-MP algorithm which combines compressed sensing techniques and classical detection theory and explores its application to sparse arrays. Sparse arrays are large undersample arrays with nonuniform spacing that provides high resolution at the cost of high sidelobes. Compressed sensing techniques are able to minimize the undesired effects of the large array, while classical...
The paper discusses design and investigation of a new approach to chirp generation for the aim of frequency deviation increasing. The structure of device that implements chirp generation based on self-phase modulation in optical fibers is given. Self-phase modulation is an effect of nonlinear optics that causes spectrum broadening of a high-power light impulse during its propagation over the optical...
Borrowing from slow-light optics, a metamaterial-based transmit array is conceived that employs a low-group-velocity serial feed line. This feed configuration facilitates a new manner of physical implementation for fast-time spatial modulation of a radar waveform based on the development of a serial-fed slotted Clarricoats-Waldron waveguide, thus realizing a physical MIMO radar implementation that...
Latest upgrades, progress, promising developments and breakthroughs are covered: PATRIOT has a GaN active electronically scanned arrays (AESAs) which gives it a 360° coverage without mechanical rotation. AMDR handles 30 times more targets and has more than 30 times sensitivity of SPY-1D(V). Can now put a whole 32 element 60 GHz T/R array on a chip. All the RF circuitry for mm-wave radars are being...
An improved reverse time migration (RTM) method is proposed for borehole radar imaging in the subsurface scenarios with layered media. The time gating function is designed and applied to the incident wave field and scattering wave field for each imaging point, which strengthens the correlation between the wave fields in time domain. A normalized zero-offset cross-correlation with gated samples is...
We propose fast direction-of-arrival (DOA) estimation of multiple sources using a single snapshot. This problem arises in many practical applications and is pertinent to automotive radar. Existing beamforming algorithms incur a high computational cost as they usually require significant zero-padding or fail to fully remove the bias that results from the spectral leakage, especially at high signal...
An analysis of the micro-motion signatures in interferometric angular velocity measurements of walking humans is given, and comparisons are drawn to micro-Doppler measurements of the radial velocity of walking humans. It is shown that the interferometric radar signal is mathematically similar to that of a Doppler radar, and that the time-frequency responses of both modes to a walking human show similar...
Recent works have shown 3D target reconstruction and total rotation velocity estimation to be feasible for interferometric inverse synthetic aperture radars (InISAR). In these techniques, it is often assumed that the target lies on an axis that is orthogonal to the group of receivers, an arrangement known as non-squint geometry. Such an assumption simplifies the resultant analysis and estimation algorithm,...
One of the desirable features in a ground surveillance radar is to provide information about what a detected person is doing. This would give a law enforcement organization ability to detect suspicious activities remotely and act accordingly. Previously, micro-Doppler radar signatures from humans were shown to have the necessary features to make that distinction. Typically, micro-Doppler signal spectrograms...
In this paper the development of a wearable 3D FMCW radar sensor system for firefighters to enhance eyesight in smoky surroundings during hazardous situations is described. In order to obtain a real-time capable, small and lightweight sensor, two orthogonal oriented frequency-scanning meander-line antennas are combined with small broadband 57 GHz to 63 GHz FMCW radar-modules. This arrangement is used...
This paper describes a novel technique for radar imaging of space objects. The approach is founded on using a small satellite near the target of interest as the receive end of a high-power ground-based radar transmitter for imaging. The small satellite is equipped with an open loop receiver for sampling and processing the observed wideband signal and a GPS receiver for orbit determination. It also...
In this paper, a new method has been presented to estimate of the Water Quality Parameters (WQPs) such as Electrical Conductivity (EC), salinity and Total Dissolved Salt (TDS). This method is mainly depended on the thermal and SAR images as an active and passive input satellite data. A Small Perturbation Method (SPM) using the Elfouhaily spectrum has been used as a physical model to calculate the...
The present work is going to investigate the potential benefits obtainable by taking advantage of the polarization diversity in a Passive Bistatic Radar (PBR) system exploiting Digital Video Broadcasting — Terrestrial (DVB-T) signals. In particular, a PBR demonstrator equipped with a surveillance array antenna able of simultaneously receiving both horizontal and vertical polarizations has been used...
The ability of radar and communication applications to share the radio spectrum will require the use of innovative agile circuit techniques for radar and communications. Reconfigurable circuits can provide real-time adjustment of operating frequency and spectral output, while maintaining system performance and maximizing power efficiency. This paper discusses recent developments in circuit optimization...
The recent explosion in demand for mobile broadband wireless communications (comms) services has created a shortage of Radio Frequency (RF) spectrum below 6 GHz. The demand for additional spectrum places pressure upon governments to release wide swaths of RF spectrum that are exclusively reserved for radar systems. This paper introduces a new spectrum sharing system architecture and set of coexistence...
Random pulse repetition interval (PRI) waveform arouses great interests in the field of modern radars due to its ability to alleviate range and Doppler ambiguities as well as enhance electronic counter-countermeasures (ECCM) capabilities. Theoretical results pertaining to the statistical characteristics of ambiguity function (AF) are derived in this work, indicating that the range and Doppler ambiguities...
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