Employing singular covariance matrix, spectral estimation methods can give high resolution results. In this paper, the original one-dimensional (1-D) spectral estimation method, which is based on singular covariance m...
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The weakness of ADS-B signals makes it vulnerable to jamming. In order to suppress jamming, the paper proposes an ADS-B anti-jamming approach with low-complexity based on a cross-antenna array. First, down-sampling th...
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ISBN:
(纸本)9781479989522
The weakness of ADS-B signals makes it vulnerable to jamming. In order to suppress jamming, the paper proposes an ADS-B anti-jamming approach with low-complexity based on a cross-antenna array. First, down-sampling the digital IF signals received by array, and estimating the covariance matrix using the down-sampled snapshots. Because of the different duration and different features of DOAs between ADS-B 1090ES signals and jamming, the larger eigenvalues of the estimated covariance matrix mainly consist of jamming. Then the array weight vector could be conducted by power inversion algorithm based on the covariance matrix obtained from the first step. Finally, jamming can be nulled by the array weight vector. Thus the proposed method would almost only suppress jamming and the output SINR would be improved sharply. Down-sampling reduces the complexity of the algorithm. Simulation and experiments results show the effectiveness of the proposed approach.
Ground penetrating radar (GPR) is often used in detecting void and cavities under the airfield runway. Delay and Sum (DAS) imaging method based on time-domain focusing of pulse-echo radar data is commonly applied in i...
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The efficiently calculate of the attitude matrix is an important subject in the Strap-down Inertial Navigation System (SINS), because the precision of its solution directly effects on the system performance. A new met...
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ISBN:
(纸本)0819460079
The efficiently calculate of the attitude matrix is an important subject in the Strap-down Inertial Navigation System (SINS), because the precision of its solution directly effects on the system performance. A new method of 3 rd order minimal parameter solution for the orthogonal matrix differential equation is used to solve the quaternion differential equation of SINS in this paper, and the numerical simulation is done as well. From the simulation result, we can see that when the new algorithm is used, the precision of the solved attitude angles is two orders higher than the classical method, and the floating-point operations is only abort half of the old one.
Cryptic disasters in airport runway will bring about serious accident like crash. In order to detect and recognize diseases timely, a time-frequency feature extraction method based on Wigner distribution is proposed i...
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OFDM multihop system is efficient scheme to save energy and extend coverage. In this paper, optimal resource allocation in OFDM multihop system, including arbitrary number of hops and subcarriers, is studied. By joint...
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ISBN:
(纸本)9781424443376
OFDM multihop system is efficient scheme to save energy and extend coverage. In this paper, optimal resource allocation in OFDM multihop system, including arbitrary number of hops and subcarriers, is studied. By joint subcarrier matching and power allocation, our goal is to maximize system capacity with the system-wide power constraint. First, we formulate the optimal subcarrier matching and power allocation problem as an optimization problem, which is a mixed binary integer programming problem and prohibitive to find the global optimum. Then, by utilizing the special structure of the system, we propose a low complexity resource allocation scheme, which is proved to be globally optimal. The simulations prove that the proposed scheme improves the system capacity.
Because ordinary users cannot quickly obtain the three-dimensional space position of aircraft in the airport terminal area through a two-dimensional display navigation map, the aircraft surveillance simulation system ...
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The combination of multihop relay system and orthogonal frequency division multiplexing (OFDM) modulation is a promising way to increase capacity and extend coverage area. For OFDM two-hop relay system with separate p...
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ISBN:
(纸本)9781424443376
The combination of multihop relay system and orthogonal frequency division multiplexing (OFDM) modulation is a promising way to increase capacity and extend coverage area. For OFDM two-hop relay system with separate power constraints, we consider joint subcarrier matching and power allocation problem to maximize the system capacity, where the relay strategy is decode-and-forward. We formulate the optimal joint subcarrier matching and power allocation problem as an optimization problem, which is mixed binary integer programing problem and prohibitive to find global optimum in terms of complexity. By separating the subcarrier matching and power allocation, we provide the optimal scheme, i.e., optimal joint subcarrier matching and power allocation. Though simplifying the system architecture, the simulation proves that the one-to-one subcarrier matching is almost optimal.
?As a kind of renewable and clean energy, wind energy has been widespread concerned by countries around the world. Recently, the global wind power installed capacity is growing exponentially. ?Wind turbines will have ...
ISBN:
(纸本)9781479989522
?As a kind of renewable and clean energy, wind energy has been widespread concerned by countries around the world. Recently, the global wind power installed capacity is growing exponentially. ?Wind turbines will have a serious impact on Air Traffic Control (ATC) communication, navigation and surveillance systems due to the complex electromagnetic scattering properties.
In this paper, a new algorithm of runways detection based on classification is proposed for PolSAR image, in which scattering similarity and structural characteristics of airport runways are used as target feature for...
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ISBN:
(纸本)9781479989522
In this paper, a new algorithm of runways detection based on classification is proposed for PolSAR image, in which scattering similarity and structural characteristics of airport runways are used as target feature for classification. Firstly, training sample templates are built by initial terrain classification with scattering similarity. Then, Bayesian classification is used to classify the whole image. Finally, morphology filtering and the runways structural features such as parallels, topologic property are used to detect real runways. Multi-look fully polarimetric SAR data acquired by U.S. UAVSAR systems is used to verify the proposed algorithm. Experimental results show that the novel method can detect runways effectively and has a low false alarm rate. Besides, the detected runways keep an intact structure and clear outlines.
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