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On 5 July 2014, a suicide terrorist set a crowded bus on fire in Hangzhou, injuring 33 passengers. Among these, 19 adult victims with the most severe burns were triaged to our center. This is a single-center, descriptive study recording the prehospital response and in-hospital treatment of these patients.Information on the attack, on-scene rescue, and patient triage was collected from public media,...
This article through literature retrieval, questionnaire and other method to investigate and analyze, and analyze the advantages of the application of virtual experiment in secondary vocational school experiment class. This paper systematically describes the related design theory basis. On this basis, overall to design platform performance, experimental modules, development tools and development process...
Advanced Genetic Algorithm(AGA) is an algorithm that could be beneficial to both the jammer suppression and subarray structure, which could obtain an array structure with relatively concentrated subarray structure and better jammer suppression. The structure of subarray level optimazation is analyzed and the signal model is presented. Subarray level optimization could suppress jammer effectively;...
In phased array at subarray level with monopulse technology, generally, analog weighting at element level are adopted for sidelobe suppression of patterns, while digital weighting at subarray level for adaptive processing. This paper studies the sidelobe suppression method for sum and difference beam by using only subarray level weighting instead of analog weighting, which is most of interest for...
Adaptive digital beamforming(ADBF) at subarray level is one of crucial techniques for phased array radar. Generalized sidelobe canceller(GSLC) at subarray level is an effective solution in the presence of array imperfections such as amplitude and phase errors, while the key lies in appropriate blocking matrix(BM) to block desired signal and adaptive weights for suppressing jammers. While at subarray...
Space-time adaptive processing technique is an adaptive processing scheme in both space and time, which could suppress broadband jammer effectively. STAP at subarray level for phased array is studied. The structure of subarray level STAP is analyzed and the signal model is presented. The space-time covariance matrix and steering vector are constructed. Subarray level STAP could suppress broadband...
ADBF is one of crucial techniques for phased array radar, which generally contains thousands of element. It usually adopts subarray configuration and can get only digital outputs of subarrays. Direct subarray weighting(DSW) configuration based on linearly constrained minimum-variance(LCMV) is an effective solution for ADBF, while the performance degrades in the presence of array imperfections such...
Subarray configuration is usually adopted in phased array radar where monopulse is used to detect the target angle by using sum and difference beam. While analog (Taylor and Bayliss taper) weighting is usually used to suppress the sidelobes of sum and difference beam. This paper presents an approach for phased array radar at subarray level based on full digital weighting at subarray level, therefore...
This paper studies the method for sidelobe suppression of difference pattern at subarray level in phased array. Sidelobe suppression of difference pattern by digital weighting at subarray level takes advantage that the hardware cost and complexity can be reduced effectively. The optimization method for subarray weights based on genetic algorithm is presented. In order to avoid being constrained on...
Optimum difference beamforming at subarray level based on LCMV criterion has an excellent jammer cancellation performance, but compared with the quiescent pattern, sidelobe level of the difference pattern remarkably increases. ADBF for difference beam at subarray level based on subspace projection can yield exactly the desired quiescent pattern in the absence of jammer, but the limitation is that...
In radar system, for sum and difference beams, Taylor and Bayliss tapers are adopted in general. For plane array, this paper suppresses sidelobes of sum and difference beams using analog and digital weightings. Analog weighting is obtained based on adaptive approach which minimizes the jammers within the whole sidelobe area. The advantage of this taper is that it can suppress sidelobes of sum and...
An approach of subarray partitioning for planar phase array radars with ADBF is presented. The architecture of subarray is optimized using genetic algorithm. With the optimized structure of the array, the sidelobe level of adaptive pattern has been well improved; meanwhile, the jammer was suppressed obviously in the direction of the jammer arrival for ADBF at the subarray level. That was demonstrated...
An architecture optimizing method in planar phased array is given based on genetic algorithm (GA). Pattern sidelobe is improved by optimizing array architecture via division of subarrays. Analyze subarray pattern and give out the flow chart of subarray segmentation. By adaptive crossover operator and independent genetic operation, traditional GA is improved. Convergence speed is accelerated and calculation...
2-D subarray level super-resolution direction finding method has an important application in phased array radar. We study the method suited for coherent sources and propose the signal model of WSF (weighting subspace fitting) algorithm at subarray level. Constructing simplified array manifolds can reduce calibration cost and expense of phased array enormously. We post-process the digital subarray...
ADBF at subarray level has important applications in phased array radar systems. We present the signal model of 2-D ADBF at subarray level, suitable for any plane phased array. We give 2-D ADBF at subarray level which can be generalized by ADBF at element level, but its limitation is that adaptive processing makes the sidelobe level of patterns increase remarkably. Therefore, we introduce 2-D ADBF...
2-D subarray level super-resolution finding has an important application in phased array radar. We study super-resolution methods at subarray level for coherent sources and propose the signal model of WSF (weighting subspace fitting) algorithm at subarray level. Constructing simplified array manifolds is an effective way to reduce calibration cost and expense of phased array largely. We post-process...
Adaptive digital beamforming (ADBF) at subarray level has important applications in phased array radar systems. This paper studies two-dimensional ADBF methods at subarray level. We present the signal model of two-dimension ADBF at subarray level. Generalizing ADBF applied to one-dimension linear array to phased array at subarray level, we can obtain two-dimension ADBF at subarray level, but its limitation...
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