This paper achieves the SAR geometric correction algorithm and makes improvements based on multi-core C6678 DSPs. To solve the insufficient real-time problem, this paper improves the geometric correction, and designs ...
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With the rapid development of Internet technology, crowdsourcing, as a flexible, effective and low-cost problem-solving method, has begun to receive more and more attention. The use of crowdsourcing to evaluate the qu...
With the rapid development of Internet technology, crowdsourcing, as a flexible, effective and low-cost problem-solving method, has begun to receive more and more attention. The use of crowdsourcing to evaluate the quality of linked data has also become a research hotspot. This paper proposes the concept of Domain Specialization Test (DST), which uses domain professional testing tasks DSTs to evaluate the professionalism of workers, and combines the idea of Mini-batch Gradient Descent (MBGD) to improve the EM algorithm, and the MBEM algorithm is proposed to achieve efficient and accurate evaluation of task results. The experimental results show that the proposed method can screen out the appropriate workers for the linked data crowdsourcing task and improve the accuracy and iteration efficiency of the results.
With the extensive application of the knowledge base (KB), how to complete it is a hot topic on Semantic Web. However, many problems go with the big data, and the event matching is one of these problems, which is find...
With the extensive application of the knowledge base (KB), how to complete it is a hot topic on Semantic Web. However, many problems go with the big data, and the event matching is one of these problems, which is finding out the entities referring to the same things in the real world and also the key point in the extending process. To enrich the emergency knowledge base (E-SKB) we constructed before, we need to filter out the news from several web pages and find the same news to avoid data redundancy. In this paper, we proposed a hierarchy blocking method to reduce the times of comparisons and narrow down the scope by extracting the news properties as the blocking keys. The method transforms the event matching problem into a clustering problem. Experimental results show that the proposed method is superior to the existing text clustering algorithm with high precision and less comparison times.
With the development of high-speed and real-time signal processing systems toward modularization, generalization and reconstruction, a method of modular design has been proposed and accepted widely. However, the incre...
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With the development of high-speed and real-time signal processing systems toward modularization, generalization and reconstruction, a method of modular design has been proposed and accepted widely. However, the increasing module types and extending production scale make the module-test challenged and the test results of modules are dispersed, which make it difficult for collection and post-maintenance. Moreover, it's difficult to perform traversal test with so many module-combinations, and this consumes excess equipments and human resources. In this paper, we proposed a concept of integrated testing, and designed a integrated testing platform(ITP) based on the Open VPX architecture. The ITP can achieve intelligent identification and resources detection of the under-test single/multiple modules after startup, and with the users' manual configurations, the ITP can then perform the traversal test automatically. Besides, the ITP provides functions such as real-time fault alarm and the test report printing. The ITP has been applied in mass testing for an Open VPX-based high-performance processing module, with multiple VLSI(Very Large Scale Integrated) circuits integrated, such as TI TMS320C6678, Xilinx Virtex-6,etc, and greatly increases its efficiency and accuracy.
For the 2D radar system, in order to improve the performance of target plots, a new algorithm based on geometric center and amplitudes of measurements was proposed, aimed at that the traditional plots centroid algorit...
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ISBN:
(纸本)9781509037117
For the 2D radar system, in order to improve the performance of target plots, a new algorithm based on geometric center and amplitudes of measurements was proposed, aimed at that the traditional plots centroid algorithm does not use the amplitude information or over-uses it. The proposed algorithm can reduce the weights of the measurements which are far away from the geometric centre, so as to obtain mere accurate range and azimuth estimations even under the circumstances of strong false measurements. Simulations show that the proposed method works better than the traditional methods.
Synthetic Aperture Radar Differential Interferometry(DIn SAR) technique is an effective tool with large coverage and high spatial accuracy for subsidence monitoring. Nevertheless, the temporal resolution is usually po...
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Synthetic Aperture Radar Differential Interferometry(DIn SAR) technique is an effective tool with large coverage and high spatial accuracy for subsidence monitoring. Nevertheless, the temporal resolution is usually poor so that rapid deformation cannot be measured due to the long revisit time of radar *** SAR Differential Interferometry technique using Global Navigation Satellite System(GNSS) as illuminator has a shorter revisit time, whereas the measurement accuracy is constrained by low signal power, narrow bandwidth and atmospheric delay error. To cope with these problems, in this paper, we propose a novel subsidence monitoring technique based on Space-Surface bistatic Differential Interferometry(SS-DI) with GNSS transmitters, where two stations consist of a reference one and a measurement one that are deployed on the ground. First, we applied a space differential processing between two stations to cancel identical errors such as tropospheric and ionospheric errors etc. Then we used a long time coherent integration to improve the signal noise ratio. Subsequently, we also utilized a time differential processing to construct double differential equations with respect to unknown deformation variables. Finally, we solved the equations to obtain a highly accurate estimation of three dimension deformation. Furthermore, an SS-DI experiment using Beidou-2 as transmitters was carried out to validate the proposed method, where a high accuracy(0.01 mm) device was utilized to simulate subsidence deformation. The experimental results reveal that the proposed method has better performance of spatial measurement accuracy of 0.53 mm compared with differential GPS method.
The combination of ground-based synthetic aperture radar (GB-SAR) and frequency-modulated continuous-wave (FMCW) technology produces a high-resolution remote sensing system that is superior in deformation measurement....
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The combination of ground-based synthetic aperture radar (GB-SAR) and frequency-modulated continuous-wave (FMCW) technology produces a high-resolution remote sensing system that is superior in deformation measurement. However, conventional focusing algorithms should be modified for GB-SAR geometry and FMCW signals. In this paper, an accurate GB FMCW SAR signal model is constructed, and a modified Omega-K algorithm is proposed to achieve optimal imaging. The algorithm is validated by simulation results.
Dear editor,Geosynchronous Synthetic Aperture Radar(GEO SAR)has significant potential when applied to hazard and disaster monitoring because of its short revisit time of approximately 24 h and its wide coverage of app...
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Dear editor,Geosynchronous Synthetic Aperture Radar(GEO SAR)has significant potential when applied to hazard and disaster monitoring because of its short revisit time of approximately 24 h and its wide coverage of approximately 1/3 of the Earth’s surface[1,2].However,its operation in the L-band makes it more
Chopping and Interleaving (C&I) jamming is a new technology to counter pulse compression radar. It can obtain partial processing gain and produce multiple false peaks, hence achieve both deception and suppression ...
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Chopping and Interleaving (C&I) jamming is a new technology to counter pulse compression radar. It can obtain partial processing gain and produce multiple false peaks, hence achieve both deception and suppression jamming effects. In this paper, the parameter estimation and suppression methods for C&I jamming are studied. With the derivation of the pulse compression result of the jamming, time-frequency analysis is applied for jamming parameter estimation;and then the jamming is reconstructed and cancelled. Because of the low estimation accuracy of the jamming time width an adaptive CLEAN algorithm was proposed to improve the suppression performance. The effectiveness of the method is verified with simulation.
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