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As to the issue of precious velocity measurement, micro-Doppler model of cooperative target was established. First, launch coordinate system was introduced to discuss conveniently. Second, two models of micro-Doppler of cooperative target were deduced. Under the condition of receiving with PLL and transponder of frequency converting, monostatic model of micro-Doppler of cooperative target was derivate...
The target echo should be simulated in the radar testing system; Meanwhile, the deception jamming signals should be generated to test the anti-jamming characteristic of radar. As the digital radio frequency memory (DRFM) can store and duplicate sampling signals with high fidelity, the testing system is a preferred method to test the modern radar targets which can not only generate multiple false targets,...
For shedding light on the properties of range-folding, Doppler-frequency aliasing, and clutter rejection in match filtering of the MIMO radar, which are not available in publications, the paper focuses on analyzing and optimizing the ambiguity properties of the MIMO radar including the unambiguous delay interval and Doppler interval, the unambiguous area and the sidelobe level in the unambiguous area...
Deformation monitoring radar is the application of ground based SAR in regional deformation monitoring. Deformation monitoring radar is based on the ground platform and has advantages of stability, controllability and repeatable monitoring, which can be used for long-term monitoring of surface mine slope, mountain slope and urban subsidence. In this paper, the application experimental study and analysis...
We present an improved log-periodic antenna structure to improve the energy transmission efficiency between antenna and diode mixer. In terahertz imaging system, the antenna and diode mixer is monolithic integrated on the same substrate because of small size. In this paper, a terahertz planar log-periodic antenna is designed at 350GHz on a GaAs substrate with thickness of 100um. Optimum impedance...
The DOA estimation is a key issue in array signal processing, and there are many effective methods, e.g., Capon, MUSIC and Capon-MUSIC algorithms, in the literature. Nevertheless, there is less compare between the DOA estimation methods and the CRB of closely spaced multiple sources with large power differences. In this paper, it is compared between the three kinds of DOA estimation algorithms and...
This paper considers the decline problem of tracking accuracy caused by acceleration estimation inaccuracy in hybrid grid multiple model (HGMM) algorithm. A new improved tracking algorithm of maneuvering targets based on CSHGMM is proposed. Grid partition is performed by estimation of the acceleration mean in current statistic (CS) model, where a fading factor is adopted to improve tracking accuracy...
This paper models the echo returned from a micro-motion target with translational motion as the hybrid sinusoidal frequency-modulated and polynomial-phase signal (SinFM-PPS). We decouple the SinFM component from the PPS one, relying on the properties of the multi-lag high-order ambiguity function (ml-HAF), then employ the time-frequency distribution(TFD)-Hough transform to get robust estimation of...
A technique is presented for estimating the primary measurements of forward scatter radar with a planar array. The space-time processing based on three-dimensional discrete Fourier transform is employed and the computation is reduced without loss of accuracy. By analyzing the Cramer-Rao lower bound, the performance of the given approach is shown. Meanwhile, the effect of the target's complex scatter...
A Digital Radio Frequency Memory (DRFM) system is designed to digitize a Radio Frequency (RF) input signal at a specific frequency and bandwidth to represent the signal adequately, and then reconstruct that RF signal after a series of process such as storage, time-delay and frequency shifting. The hardware requirement for general purpose DRFM system is analyzed and the hardware architecture based...
Quasi geosynchronous SARs are unique in their continuous imaging capabilities, providing new applications and enhancing the existing ones. However, the large integration time, minutes to hours, introduce clutter noise due to atmospheric turbulence, moving targets, and other minor effects like platform vibration or clock jitter. A proper modelling of these effects provide a qualitative and quantitative...
Phase-Modulated PRC-CW Radar is widely used because of its high range resolution and speed resolution. When a large range of distance detection and a wide Doppler dynamic range are needed, the computation of capturing the target will be large. In order to reduce the computation, an orthogonal coding waveform is proposed in this paper, which can reduce the computation by more than one order of magnitude...
Synthetic aperture radar (SAR) systems have been successful in applications of monitoring stationary terrain. Recently, bistatic SAR systems using GNSS satellites as illuminates attract intensive attentions in the research field of SAR. Due to the abundant frequency resources of GNSS systems, high resolution synthetic technology in range dimension is of great significance to make full use all of these...
In Beijing, there has been serious land subsidence due to overexploitation of ground water in recent years. It's becoming crucial to evaluate the spatial and temporal heterogeneity for hazard control. In this study, we derived spatial-temporal evolution of land subsidence in Beijing plain area using 48 scenes of ENVISAT-ASAR data by Permanent Scatterer (PS) InSAR techniques. The monitoring results...
Radon-Fourier transform (RFT) realizes the long-time coherent integration to detect weak targets. However, because of discrete pulse sampling, finite range resolution, and limited integration time, the "blind-speed side lobes (BSSL)" of RFT may inevitably appear in real application. This paper proposes Random Carrier-Frequency Radon-Fourier transform (RCF-RFT). It is a good solution for...
Synthetic aperture radar (SAR) on a satellite or a plane is a useful tool for ship target detection because it can work in all weather conditions, day and night. However, speckles of sea clutters and heterogeneous sea regions in SAR images will pose challenges on a task of automatic ship detection. In this paper, we propose a visual saliency-based method for ship detection in SAR images. The proposed...
This paper introduces an algorithm based on the context of MRF (Markov random field) model, and this method achieved oil spilling detection and segmentation. In this paper, the two important elements are initial labelling field and potential parameter estimation. The algorithm model chooses optical pyramid of saliency map as initial label field and Ising model as segmentation function. Using the GMM...
Different azimuth targets have different Doppler centroid and different time support domain in slide spotlight synthetic aperture radar. Thus, it is hard to weighting window on the echo in slide spotlight mode. This paper proposed an azimuth weighting method of slide spotlight SAR based on subaperture chirp scaling algorithm. Firstly, the sub aperture number of the algorithm is discussed based on...
This paper compared the differences between monostatic SAR and bistatic SAR by introducing the spatial spectrum theory. The signal models of different radar systems are analyzed. The SAR image processing is considered as a Fourier transformation in the spatial spectrum where the SAR echo corresponds to the sampling point. Three kind of SAR system are simulated using method of moment which ensures...
An ultra-broad band transverse electromagnetic(TEM) exponential horn antenna is designed. A balun is used for the impedance taper along the length of the proposed antenna to improve the antennas impedance characteristic and adapting an unbalanced plane line to a balanced one. The antenna is fabricated and tested. Broadband attributes are demonstrated with measured return loss of better than −10 dB...
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