?ADS-B IN and TCAS Once ADS-B IN technology can be achieved onboard, it can be used to replace conventional TCAS. ?Conventional track generation methods Kalman filtering, particle filtering, motion models and data min...
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ISBN:
(纸本)9781479989522
?ADS-B IN and TCAS Once ADS-B IN technology can be achieved onboard, it can be used to replace conventional TCAS. ?Conventional track generation methods Kalman filtering, particle filtering, motion models and data mining ?ADS-B data more than 280 million, CAT021 format v0.26.
Automatic Dependent Surveillance-Broadcast (ADS-B) is vulnerable to spoofing interference which will lead to the failure of Air Traffic Management (ATM) systems. This paper proposed an effective approach to detect and...
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ISBN:
(纸本)9781479989522
Automatic Dependent Surveillance-Broadcast (ADS-B) is vulnerable to spoofing interference which will lead to the failure of Air Traffic Management (ATM) systems. This paper proposed an effective approach to detect and suppress the spoofing interference based on a cross-antenna array without estimating the direction of arrival (DOA) of the received signal. Firstly, the location of target is received by the antenna array. Then the azimuth and the elevation according to the antenna array are obtained based on the locations of target and the central element of array. Secondly, the signal from the estimated direction is suppressed by projecting the received signal onto the orthogonal complement space of estimated steering vector. Finally, the target is recognized as a real target or spoofing according to the spoofing decision algorithm. The simulation results show the effectiveness of the proposed algorithm.
For GPS(Global Position System) receivers, the nonstationary interferences may result from rapid relative motion between interference and GPS receiver, a change in the number of interferences and impulse interference,...
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For GPS(Global Position System) receivers, the nonstationary interferences may result from rapid relative motion between interference and GPS receiver, a change in the number of interferences and impulse interference, etc. The conventional interference suppression algorithms based on covariance matrix are ineffective with nonstationary interferences. By utilizing the sparse representation, a new kind of nonstationary interference suppression algorithm is proposed in this letter. In particular,a greedy sparse interference space reconstruction algorithm is utilized to directly estimate the received interferences instead of DOA(Direction of Arrival) estimation. The interferences are suppressed by subtracting the estimated interferences for every snapshot without covariance matrix estimation. There are two typical advantages:(1) the proposed algorithms do not require the number of interferences;(2) the proposed algorithms are robust for both DOA separation of interferences and grid mismatch of sparse representation. The simulated results demonstrate the effectiveness of the proposed algorithms.
➢ Airport is an important military and civilian facility. Its automatic detection is very necessary in many fields, such as military reconnaissance, precision strike, emergency rescue, aircraft navigation and so on. ➢...
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ISBN:
(纸本)9781479989539
➢ Airport is an important military and civilian facility. Its automatic detection is very necessary in many fields, such as military reconnaissance, precision strike, emergency rescue, aircraft navigation and so on. ➢ Runways are the typical and stable feature for airport detection.
➢ 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 hav...
➢ 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.
When detecting low-altitude windshear with airborne weather radar, the real signals are usually covered with strong clutter. In this paper, according to the airborne phased array weather radar, a novel method of low-a...
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ISBN:
(纸本)9781479982332
When detecting low-altitude windshear with airborne weather radar, the real signals are usually covered with strong clutter. In this paper, according to the airborne phased array weather radar, a novel method of low-altitude windshear speed estimation based on Space-Time Amplitude and Phase Estimation (APES) is proposed to solve the above problem. The method constructs the space-time adaptive processor with APES theory to obtain clutter suppression and match the windshear signal, then estimates the signal doppler frequency which resulting in the wind speed estimation. The experimental results show that the proposed method can achieve a superior clutter suppression performance and an accurate wind speed estimation in high clutter-to-noise ratio and low signal-to-noise ratio.
In the complex electromagnetic environment, the Global Navigation Satellite System(GNSS) wasseriously influenced by the interference. The anti-jammingalgorithm based on the uniform array have been widely used in GNSS ...
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In the complex electromagnetic environment, the Global Navigation Satellite System(GNSS) wasseriously influenced by the interference. The anti-jammingalgorithm based on the uniform array have been widely used in GNSS interference suppression technology, but the number of the interference is limited by the number of the antenna sensor. This paper proposed an interference suppression algorithm based on the extended array, the algorithm could suppress more interference than the number of antenna sensor. Firstly, the covariance matrix of the non-uniform array is vectorized. After that, the spatial smoothing is used to build up the rank of the covariance matrix. With the smoothed covariance matrix, power inversion algorithm is used to estimate the directions of the interference. Then, forming an overdetermined equation based on the interference subspace and an arbitrary signal's steering vector, whose direction is different form the interference. Finally, solving its least-squares solution to get the optimal weight, which can form nulls in the direction of interference without affecting the useful signal. The simulation results verify the effectiveness of the proposed algorithm.
Space-Time Adaptive processing(STAP) is an effectivemethod to suppress interference in Global Navigation Satellite System(GNSS).But in high-dynamic environment, conventional adaptive anti-jamming algorithms are invali...
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Space-Time Adaptive processing(STAP) is an effectivemethod to suppress interference in Global Navigation Satellite System(GNSS).But in high-dynamic environment, conventional adaptive anti-jamming algorithms are invalid since jammers may easily move out of the array pattern nulls. To solve this problem, a new null-widen method based on the Laplace distribution model is deduced in this paper, the method can get wider null at direction of *** this method is computationally intensive by using STAP, thus a new null-widen method based on reduced-dimension multistage wiener filters(MWF) is deduced here. It has proved in simulation section that the new method can get better performance in few snapshots.
The paper proposes a spoofing interference suppression algorithm for multiple spoofing interferences existing simultaneously. First, the signals which received from the reference antenna array are captured. The inform...
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The paper proposes a spoofing interference suppression algorithm for multiple spoofing interferences existing simultaneously. First, the signals which received from the reference antenna array are captured. The information about visible satellite signals' Doppler frequency and code delay are acquired. Using these information, we can reconstruct the visible satellite signals. Then, the visible satellite signals' steering vectors are estimated by calculating cross-correlation between the estimated visible satellite signals and the antenna array received signals. Utilizing the normalized cross-correlation coefficients of the visible satellite signals' steering vectors to detect spoofing interference and its steering ***, the proposed algorithm constructs an orthogonal projection matrix based on spoofing interference' steering *** interference are suppressed by utilizing the constructed orthogonal projection *** proposed novel spoofing interference suppression algorithm can simultaneously suppress multiple spoofing interference, which does not need to know the array manifold in advance and the DOAs(Direction of Arrival) of satellite signals and spoofing interference.
Currently, there have been many studies of interference suppression for satellite navigation systems. Power minimization approach is an effective interference suppression algorithm. It forms automatically deep nulls i...
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Currently, there have been many studies of interference suppression for satellite navigation systems. Power minimization approach is an effective interference suppression algorithm. It forms automatically deep nulls in the DOAs(direction of arrival) of interferences without prior information about the DOAs of satellite signals and interferences. However, the power minimization approach can not provide flat gains in other directions. Thus there will be fluctuation in the beampattern, especially when the number of snapshots is not enough. It means that the desired satellite signal may be partly suppressed when they locate in the shallow nulls. In this paper, by combining eigenvalue thresholding method and l1-norm constraint, we propose a new interference suppression algorithm to suppress interferences and provide flat gains in all directions except that of interferences. The difference between the new algorithm and the conventional power minimization approach lies in the improvement of covariance matrix which is constituted based on the main eigenvalues and corresponding eigenvectors of covariance matrix. In addition, an explicit l1-norm constraint on the beam gains is exploited to provide flat gain in all directions except that of interferences. When there are interferences and spoofing, the spoofing is generally suppressed heavier than the authorized signal. It will decrease the power difference between the spoofing and authorized signals. Thus it will degrade the performance of subsequent spoofing detection. So the proposed algorithm also can be applied to the spoofing detection in satellite navigation systems. The simulations demonstrate the effectiveness of the proposed algorithm.
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