The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
An ultra wideband antipodal vivaldi antenna is designed to cover from 2 to 10 GHz in this paper. The proposed antenna in the whole bandwidth with VSWR less than 2 and gain varies from 2 to 10 dBi. It also exhibits symmetric radiation patterns in both E-plane and H-plane. Measured results show good performance of the proposed designs.
This paper proposes a new SAR (Synthetic Aperture Radar) image watershed segmentation method based on contextual statistical features analysis. This method firstly homogenizes all the sub-blocks of image by analysing statistical features, and then extracts the feature of each homogenized sub-block. Finally, the watershed area of this image can be segmented by means of Otsu algorithm. The experimental...
It had originally been shown in the literature that a MIMO full/thin array radar system (consisting of a full transmit linear array of N elements having X/2 spacing and a collocated, parallel, linear thinned receive array having NX/2 spacing) is equivalent to a full array of N2 elements having X/2 spacing and thus achieves N times the accuracy and resolution as a conventional full array of N elements,...
In this paper, a dispersive conformal FDTD method have been proposed to accurate model the interface between two adjacent dispersive mediums. The method is based on the technology of area average between two adjacent dispersive interfaces, which is different from existing dispersive conformal FDTD schemes which involve with the interface between free space and dispersive medium. Numerical results...
Existing techniques for remote sensing of ocean surface conditions by HFSWR are predicated on the assumption that the Doppler spectrum recorded at a given time delay and direction of arrival can be associated with the ground range and bearing corresponding to great circle propagation over a smooth surface. In this paper we investigate the consequences of the spatio-temporal modulation accumulated...
Air moving target indication (AMTI) is an important and challenging application for spaceborne sparse radar. The distributed sparse array radar can achieve larger maximum functional range by power synthesis and higher spatial resolution by aperture synthesis. However, the undersampling of sparse array brings grating lobes and high side-lobes in the synthesized pattern, which will cause the blind-zone...
Multicarrier Phase-Coded (MCPC) signals have been recently introduced to radar systems as a kind of wideband signal. In this paper we study the wideband ambiguity function (WAF) of multicarrier phase-coded signals. Based on the fact that scattering characteristics of target varies with frequency, we propose an approach which adaptively changes the transmitted frequency weights to improve radar's WAF...
Constant False Alarm Rate (CFAR) algorithm is an important technology of radar system. It can provide optimal signal detection performance via maintaining a constant false alarm rate. However, the computational workload of estimating the clutter power of every data unit can be high. Thus, a software pipeline method for CFAR on the Digital Signal Processor(DSP) of TI's latest series C6000 family is...
Transmit/Receive (T/R) modules are key components in Active Electronically Scanned Array (AESA) for advanced airborne radar, and their performance affects the capability of airborne AESA radar in several aspects. In this paper, a procedure is proposed with the tradeoff design of an AESA radar between the power-aperture product (PAP) and the peak-to-side lobe ratio (PSLR) of its antenna. While the...
The multistatic radar cross section of the stealthy objects is obvious higher than that of the monostatic radar. Using the multistatic radar based on geosynchronous/ground can improve the detecting probability of stealthy targets. Under the condition of employing space-based multistatic radar configuration, the integration and detection methods for such long dell time should deal with the problem...
The short-range clutter of airborne forward-looking radar couples seriously in range and Doppler, which seriously degrades the performance of the space-time adaptive processing (STAP) algorithm in ground moving target detection. In order to overcome the problem of homogeneous samples, we propose a weighted sample selection strategy. In this method, the traditional generalized inner product value is...
This paper proposes a target association algorithm with fuzzy inference on satellite electronic information, aiming at the association difficulties caused by the following problems: false alarms may exist in the observation, radar emitters can change radiating parameters and there are multiple platforms equipped with the same type of radar emitters in the observational scenario. Firstly, the electronic...
Pulse tracking is extensively applied in sampling guidance for intra-pulse analysis, antenna scan analysis, special signal accurate orientation in electronic intelligence (ELINT), as well as in passive radar seeker (PRS). In some real-time application such as PRS system, existed tracking algorithm cannot deal with complex modulated pulse repetition interval (PRI) as wobulated PRI and linear sliding...
An electromagnetic in-house parallel EM solver for RCS computation of complex target is presented in this paper. The solver makes use of a weak formulation based on double curl vector wave equation discretized with the higher-order isoparametric curl-conforming tetrahedral finite element rigorous implementations of Nedelec first family of elements. For RCS analysis, a non-standard mesh truncation...
The identification of clutter is an important method to mitigate its influences on radar target detection and Doppler centroid provide an effective feature to identify the moving or static clutter. However, Doppler estimation accuracies closely related to the length of the coherent processing intervals(CPI), and the Doppler centroid estimation in a small CPI is challenging. In this study we analyzed...
Source separation plays an important role in array signal processing applications, such as anti-jamming, multi-signal detection, etc. The performance of source separation need to be analyzed, which can also be indicated by the array performance index, output signal-interference-noise-ratio (SINR) and beam pattern. The blind signal separation (BSS) has been mostly used to separate mixed signals, compared...
The existing direction of departure (DOD) and direction of arrival (DOA) estimation algorithms suffer from sensitivity to the mutual coupling, gain-phase errors and sensors position errors of the transmit and receive array for bistatic MIMO radar. By applying two well-calibrated instrumental sensors in both transmit and receive arrays, a novel angle estimation algorithm, with the combined influences...
The paper studies the formation design and baseline optimization of multiple Geosynchronous SAR (GEO SAR) interferometry. First, the formation configuration of current low Earth orbit SAR (LEO SAR) satellites are analysed in detail, and the various configurations are catalogued and modelled. Then, considering the characteristics of GEO SAR, the potential formation configurations of the twin GEO SAR...
To solve the problem of inaccuracy and bad anti-noise performance in traditional methods on precession period estimation, a novel approach is suggested. The approach is based on the exploiting average magnitude difference function (AMDF) and autocorrelation function (ACF). No a priori information about ballistic target under classification is required for estimation of period. The trend term of AMDF...
Landslide occurring around big reservoir and other water conservancy facilities affects the displaced residents' living and the safety seriously. Recently, as a newly rising remote observation technique, ground-based synthetic aperture radar interferometry has been development and widely used in related investigation and assessment field since it has efficiency and accuracy advantages on monitoring...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.