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A new location method is proposed in this paper. The location method is based on the spaceborne radar detecting system. Three pulse radars on satellites locate the position by measuring the time delay difference of the direct-path-wave and the target echo. The new location method and the location function derivation are proposed, and the location precision is analyzed and simulated in this paper.
The development of receiving dual band or multiband antennas has witnessed explosive growth driven by their usefulness in the satellite navigation systems in recent years. A low profile dual-band circularly polarized (CP) antenna working at BD-B3 (1268MHz) and GPS-L1 (1590MHz) frequencies is designed in this paper. Four rectangular swells are added around the antenna to tune the resonant frequency...
The characters of sea clutter are studied, and the faults of restraint method using the single radar are indicated. Then the restraint method of distribution detection of multiple radars is proposed, with the feasibilities and advantages studied. Next the detailed algorithm is discussed. Further the proposed method is tested by the real data from surveillance radar, the effect of which is greatly...
FMCW radar with deramping technique has many advantages comparing to traditional pulse radar. But the expressing of signal error becomes more complicated. The distortions on amplitude and phase are unavoidable for wide bandwidth and wide pulse signal, which have a serious impact on the imaging quality. Aiming at the problem of signal error correction, the echo signal model of FMCW radar with amplitude-phase...
The problem of signal detection in unknown Gaussian interference with an adaptive array is considered in this paper. A modified Generalized Likelihood Ratio Test (GLRT) detector is suggested to improve the performance of Kelly's GLRT, when the sample that estimating the covariance matrix is limited. The modified GLRT detector proposed in this paper is noiseless unloaded GLRT (NU-GLRT). Advantages...
In this paper, to suppress the digital radio frequency memory (DRFM) false target jamming, we introduce a jamming recognition-based method. The method first extracts mixed target and jamming samples, then computes adaptive weights by subsections of mixed samples, finally recognizes the jamming samples according to the adaptive power residue (APR) criterion. Numerical examples are provided which verify...
This paper designs a traditional rectangular patch antenna and high-impedance surface (HIS) based patch antennas working at WIFI frequency (2.45GHz). The impedance matching and radiation pattern of the traditional patch antenna and the HIS patch antennas are compared through both the full-wave simulation and measurement. These results show that the HIS can suppress the surface waves and reduce back...
With dynamical change of the environment, the optimal allocation of search resources is required for multi-area search of phased array radar. A parameter optimization model based on the weighted average discovering range of the penetration target is built in this paper. By joint search load allocation and search frame time adjustment optimal performance is achieved with initial search resources. Then...
On the basis of the polarimetric distance measurement, this paper presents an improved method of change detection through a complete model-based decomposition of the polarimetric synthetic aperture radar (POLSAR) co-variance/coherency matrix data. Due to the capability of accurately characterizing the structural features for polarization decomposition, the proposed method first utilizes the Freeman-Durden...
This paper proposes a carrier tracking method based on the Kalman Filter (KF) for the high dynamic target tracking. In the proposed method, the carrier tracking is achieved via the phase locked loop (PLL) serially assisted by the frequency locked loop (FLL). Furthermore, based on the KF theory, we analyse the carrier tracking loop and get the system equation of PLL and FLL. The proposed method can...
This paper deals with the road and vehicle detection problem in highway scene for automotive radar which uses frequency-modulated continuous-wave (FMCW) signals and antenna array. Due to the automotive radar's low angle resolution, targets such as guardrails on road edge interfere with the vehicle detection and bring difficulties to the distance-velocity decoupling. We proposed an approach with Hough...
In this paper, the wireless communication stable signal is decomposed into three components, i.e., communication waveforms, individual modulations and system noise. From the eigenvalue spectrum of the observed signal, it is found that the primary components, i.e., the several largest eigenvalues, correspond to the communication waveforms while those minimal components are caused by the noise. Meanwhile,...
The three-dimensional (3-D) imaging technique based on array antenna is an important way to achieve a 3-D image. However, conventional imaging radar system requires a large number of antenna elements. Both the cost and complexity of the system are increased. This paper refers to the principle of MIMO radar and introduces a near-filed optimization method for sparse array designing based on the equivalent...
Ship detection of harbors is significant to defeat enemy's firepower before forming. Realization of ship detection in SAR harbor images accurately and efficiently is a hot topic nowadays. The complexity of the inner harbor and the uncertainty of target types make it difficult to achieve effective ship target detection of harbor SAR images and the detection procedure is complicated. The paper analyzes...
Aiming at solving the problem of closely spaced targets and glint noise of measurement in the tracking process of sea surface multitarget, this paper proposes a new track initiation algorithm. Compared with the traditional algorithms, the proposed algorithm combines the modified Hough transform with ellipse validation gate to form a new structure, and the maximum likelihood rule is adopted to cut...
High frequency surface wave radar (HFSWR) is a kind of effectively detecting target over the sea horizon radar system which has been widely used because of excellent performance. Taking the advantages of Multiple Input Multiple Output (MIMO) radar's technology, new optimized HF-MIMO radar is introduced in this paper which promotes the Woodward's ambiguity functions to HF-MIMO radar and produces original...
In this letter, a novel tri-band frequency selective surface (FSS) is designed to be used as the subreflector for reflector antennas. The FSS mainly consists of two layers of a square loop reflecting the linear polarization electromagnetic waves in Ku band (12.3 GHz–15.2 GHz) and a hexagon around with a hexagonal ring transmitting the circular polarization electromagnetic waves in Ka bands (18 GHz–21...
The two-dimensional (2-D) Capon method is commonly used in the post-processing of the synthetic aperture radar images. In applications, the covariance matrix of the observation is estimated by vectorizing the 2-D data along one direction and then calculating the matrix in the same way as the 1-D case. This operation may arouse the problem of memory overload and estimation inaccuracy. By enduing the...
Interferometric synthetic aperture radar (InSAR) can realize the elevation extraction of the target. Through increasing the degree of freedom (DOF) during the topography calculation, multi-frequency InSAR technology can further achieve high-accuracy elevation reconstruction in steep terrain. Although the maximum likelihood estimation (MLE) method is widely used in the signal processing of multi-frequency...
Water region detection in SAR image is one of the significant applications for early warning of flood disaster. In this paper, a hierarchical method is proposed to detect water region in SAR images. The detection is a hierarchical process, and can be divided into two main stages: Bag of Visual words (BOV) representation based candidate region extracting, and false-alarm elimination based on topological...
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