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In through-the-wall target localization area, wall effect including absorption and refraction will arise, wall effect needs to be compensated. If wall parameters including thickness and dielectric constant are exactly known, the target can be compensated to its correct position. In this paper, based on the transmitting model of through-the-wall radar, we deduced the Cramer-Rao lower bound (CRLB) of...
Two-dimensional Multiple Input Multiple Output (MIMO) array can form the high-resolution three-dimensional (3D) image of the near-filed target, Azimuth resolution of 3D imaging depends on angle of antennas and targets. The further distance between arrays is, the worse result of azimuth resolution we get. In this paper, we propose a method based on highresolution 3D imaging of depth compensation, which...
In this paper, the autofocus compressed sensing (ACS) imaging method is proposed to obtain the imagery with some unknown parameters in the forward model. The proposed method updates the unknown parameters of the measurement matrix and constructs the imagery alternately within an iterative framework. The unknown parameters, denoted as hyperparameters, are estimated using the nonlinear conjugate gradient...
Due to the attenuation effects of walls, the signal to noise ratio (SNR) for targets indoor is unavoidably decreased, which seriously influences the quality of through-the-wall imaging (TWI) results. To suppress the deterioration of noise and clutters yield by walls, an adaptive noise power spectrum estimation method is put forward in this paper to enhance the performance of TWI. Through a combination...
OpenMP 4.5 allows performance portability by enabling users to write a single application code and run it on multiple types of accelerators. Our goal is to deliver a high-performance implementation of OpenMP into the Clang/LLVM project. This paper describes our initial work to fully support code generation for OpenMP device offloading constructs. We describe a new driver implementation to handle compilation...
The Clang implementation of OpenMP® 4.5 now provides full support for the specification, offering the only open source option for targeting NVIDIA® GPUs. While using OpenMP allows portability across different architectures, matching native CUDA® performance without major code restructuring is an open research issue.In order to analyze the current performance, we port a suite of representative benchmarks,...
This paper addresses a biomedical application of customized signal processing using the ultra-wideband impulse (IR-UWB) radar which realizes the noncontact heartbeat and respiration rate detection. Microwave radar technology offers a noncontact, quick cardiopulmonary monitoring technique and has potential for biomedical applications. We studied the effect of suppression to remove the stationary background...
The ghost clutter deteriorates target detection in through-the-wall imaging and is difficult to remove without the building structure information. In order to enhance the performance of ghost mitigation, a novel waveform optimization method is put forward in this paper to improve the signal to clutter ratio (SCR). Experiments on practical echo data further illustrate the improvement of SCR while keeping...
Circular synthetic aperture radar (CSAR) can provide high-resolution image. The anisotropic scattering information is mapped on the 2D image during the imaging procedure, which degrades imaging quality and causes information loss. In this paper, a multidimensional scattering function estimation method is proposed to extract the anisotropic information, including amplitude varying and scattering center's...
Low frequency ultra wideband (UWB) synthetic aperture radar (SAR) has shown a great potential when vehicle-size objects are obscured in foliage. The studies imply an aperture angle of at least 180° to include the strongest (broadside) response when the target orientations are unknown. However, the aperture angle of the linear SAR (LSAR) is limited. By using circular traces, the aperture angle of the...
In this paper, the auto-focusing compressed sensing (ACS) algorithm is proposed to retrieve behind-the-wall image with unknown wall parameters. The ACS algorithm proposed updates the measurement matrix and constructs the behind-the-wall image alternately within an iterative framework. The nonlinear conjugate gradient method is used to estimate the wall parameters, where the gradient functions in analytical...
We describe a bistatic low frequency ultra-wideband SAR experiment and present measurement results. The bistatic SAR system, operating in the P band, is based on a P band UWB SAR system as airborne transmitter and the other P band radar system as the ground-based receiver. Monostatic SAR data can also be acquired simultaneously. In November 2015, a measurement campaign was conducted in Shaanxi Province...
This paper addresses a noncontact measurement application of customized signal processing using the impulse radio ultra-wideband (IR-UWB) radar to realize the rotational speed detection. Microwave radar technology offers a noncontact, quick, accurate technique and has potential for industrial applications. We studied the effect of suppression to remove the stationary background clutter, and separated...
Life signal detection of human beings behind an obstacle is a keen research topic in recent years. In this paper, a singular spectrum analysis (SSA) based human life signal detection approach is proposed. SSA is a nonparametric spectral estimation method, and is widely used in time series analysis. SSA can decompose a time series into a sum of components, such as trend, periodic components and noise,...
Multistatic radar system has a great potential for human detection and tracking for its fine localization precision, wide coverage and good observability. T-RN (one transmitting antenna and N receiving antennas) radar system is the most popular multistatic radar structure. In this paper, the localization performance of T-RN radar is evaluated using Cramér-Rao lower bound (CRLB). The localization precision...
Human target detection and tracking have great potential in military, safety, security and entertainment applications. In this paper, a complete processing procedure is proposed for human tracking in foliage-penetration environment by multistatic radar. It consists of five main steps, including clutter suppression, target detection, measurement estimation, target localization and target tracking....
Human target indication and detection are widely used in military and civil applications. For stationary human targets behind an obstacle, the micro-motion caused by vital sign results in a fairly low signal-to-clutter-and-noise (SCNR). This study presents an iterative singular vector decomposition (ISVD) based micro-motion indication method for detecting human targets with through-the-wall radar...
With the improvement of processor and SDRAM performance, the performance of SDRAM controller becomes the bottleneck of the system performance. In this paper, a Tow-Level Buffered SDRAM controller is proposed, and its design and verification are described. To some extent, the controller improves the throughput of the processor for the SDRAM memory, and provides a solution for the design of high performance...
It is a challenge to detect and identify the targets in the foliage-penetration environment. Radar is superior to other sensors in this poor visibility condition. The micro-Doppler signature is one of the most prominent information for target classification and identification in radar applications. In this paper, a complete procedure is proposed for human micro-Doppler signature extraction in the...
In this paper, a novel method of spatial resolution analysis for low frequency (LF) ultra-wideband (UWB) bistatic forward-looking SAR (BFSAR) is presented, which is based on the wavenumber domain spectrum support of point target. First, the imaging geometry and signal model of the LF UWB BFSAR are established, and the wavenumber domain spectrum support of the point target is analyzed. Then, the analytical...
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