To address the performance degradation of traditional underwater target localization algorithms in high-speed motion scenarios, this paper proposes a vertically moving method based on interference feature matching using single hydrophone. Due to overlapping fringes time–frequency domain, first employs two-dimensional homomorphic filter separate different types while removing line-spectrum interference. Then, theoretical period database is constructed, and performed achieve target. Simulation...

For targets with complex motion, the echo of inverse synthetic aperture radar (ISAR) is a time-varying frequency signal in azimuth. Hence, traditional range-Doppler (R-D) algorithm based on constant invalid. In this letter, novel ISAR imaging method for motion presented. The azimuth characterized as an amplitude-modulated (AM)-cubic phase signal, which closer to real scene, and Radon transform cubic chirplet decomposition (RTCCD) proposed process signal. By introducing improved function...

Target direction-of-arrival (DOA) estimation is often difficult in the presence of strong interference—especially when target DOA very close to interference DOA—since signal can mask weak and make hard. To address this problem, an efficient sparse method for proposed paper, which effect on significantly reduced. An on-grid version grid evolution technique then developed nonuniformly refine grid, thereby reducing computational complexity while retaining reasonable accuracy. Numerical...

Acoustic tonals, radiated by underwater and surface vehicles, are an important feature for passive sonar detection. An adaptive line enhancer (ALE) is usually employed in systems as a preprocessing step to enhance the acoustic tonals from these vehicles. Unfortunately, performance of conventional ALE limited high steady-state misadjustment, which caused weight noise adaptation process. This paper makes use frequency-domain sparsity develop better ALEs sonars. The proposed performed frequency...

Based on high speed moving target robust high-resolution direction of arrival (DOA) estimation problem under low signal-to-noise ratio and a small number snapshots in the underwater acoustic vector signal processing framework, novel spatial spectrum model combined with compressive sensing method is proposed. By studying sensor structure, generalized temporal filtering based sound pressure particle velocity treatment presented. According to matrix prefiltering theory, new filter stopband...

Adaptive line enhancers (ALEs) have been widely used in passive sonars for enhancing narrowband discrete components (known simply as lines or tonals) radiated by surface underwater targets. Unfortunately, the performance of conventional ALE based on least‐mean‐square (LMS) adaptive algorithm is limited high steady‐state misadjustment, which limits output signal‐to‐noise ratio (SNR) ALE. To break through limit ALE, this study proposes a sparsity‐based (SALE). The SALE takes into account...

A general digital modulation recognition method is proposed for common M-ary modulations. coarse executed, then different algorithms are used to estimate the order of modulation. The estimation number spectrum peaks modified and a novel algorithm MASK MQAM presented. Simulations results show that rate this structure can reach 92% MFSK, MPSK when SNR above 6 dB, MQAM, higher required.

The discrete Fourier transform (DFT) of observation sequence is usually used in the detection tonal signal. A tone without any prior information cannot be guaranteed to lie exactly on DFT frequency bin, which will degrade performance detector based DFT. In this work, authors study problem for a deviated from bin. generalised likelihood ratio utilising adjacent bins designed. Theoretical analysis, computer simulations, and lake experiment show that proposed robust against deviation more...

Capon beamforming is often applied in passive sonar to improve the detectability of weak underwater targets. However, we have no accurate prior information direction-of-arrival (DOA) target practical applications sonar. In this case, beamformer will suffer from performance degradation due steering vector error dominated by large DOA mismatch. To solve this, a new robust approach proposed. The essence proposed method decompose actual into two components oblique projection onto subspace and...

Inverse synthetic aperture radar (ISAR) scaling can give the scatterers' absolute coordinate, which is premise of ascertaining target's size and recognizing target. In this paper, we present an accurate ISAR method. First, signal characteristic in cross-range dimension analyzed, problem rotational velocity (RV) converted to estimation chirp rates. Second, estimate rates, integral Lv's distribution ordinary least-squares are proposed for smooth targets maneuvering targets, respectively....

Aiming at the problem of traditional orthogonal frequency division multiplexing (OFDM) communication system performance degradation when channel is subjected to complex multi-path and frequency-selective deeply fading, a chirp spread spectrum (CSS) OFDM underwater acoustic called CSS-OFDM proposed in this paper. The spreads signals, whose sub-carriers are modulated into same rate, different center signals with overlapped bandwidth. Dispreading after coherent channel, receiving end, will be...

For the sonar arrays mounted on an unmanned underwater vehicle (UUV), direction-of-arrival (DOA) estimation of far-field (FF) weak sources is influenced by near-field (NF) interferences generated from radiated self-noise UUV and FF simultaneously. To address problem, a sparsity-based DOA method resistant to NF proposed in this paper. This isolates signals sparse reconstruction. Additionally, subspace projection applied masking problem target signal strong spatial domain, effectively...

Direction-of-arrival (DOA) estimation in a spatially isotropic white noise background has been widely researched for decades. However, practice, such as underwater acoustic ambient shallow water, the can be colored, which may severely degrade performance of DOA estimation. To solve this problem, paper proposes method based on sparse Bayesian learning with modified model using vector hydrophone arrays. Firstly, an applicable linear is established by prolate spheroidal wave functions (PSWFs)...

Domino wireless power transfer (D-WPT) has excellent advantages in long-distance supply for equipment complex spaces unsuitable maintenance. A simple receiver (Rx) will reduce the failure rate and system maintenance costs. This paper proposes a D-WPT with battery State of Charge (SOC) perception at transmitter (Tx) adaptive adjustment constant voltage (CV) current (CC) output. Specifically, we construct two-port network circuit model n-coil propose SOC identification method that uses Tx as...

A spatial rotation technique in application to unmanned underwater vehicle (UUV) sonar arrays is proposed. The essence of the rotate signals interest from array coordinates geodetic while providing robustness against interferences and preserving white noise property at output. Convex formulation matrix design problem derived using semi‐definite relaxation optimal solution obtained by rank‐one decomposition theorems. Using authors’ technique, subspace‐based direction arrival estimation...

Algorithm based on MVDR using single acoustic vector-sensor affords a new way for DOA estimation, and the influence of non-consistency character breadth capability estimation is deeply researched, corresponding expression special spectrum educed as well. The result analysis in theory simulation shows that apex broaden width warp. In allusion to condition between press velocity channels, modified algorithm power channels advanced. resolution better than conventional algorithm, processing data...

The microscopic structure characteristic of low frequency sound propagation in shallow water is that a stable space-frequency interference represented by waveguide invariant exists. Both the scalar field and vector determine all features acoustic field. characteristics are investigated. theoretical analyses mechanism pressure spectrum, kinetic energy density intensity flow spectrum conducted, numerical simulation studies Pekeris performed, sea trials for broadband source radiation properties...

We present an efficient approach for the sub-regional multiple-source detection. The essence of this is to extract characteristic components signals interest (SOIs) from estimated signal-plus-interference subspace by a matrix filter. Compared with some other spatial filtering-based approaches, it has two significant advantages. First, since power each source in normalized, proposed effective filter out interferences regardless their strengths. Second, would not reduce dimension SOIs, thus,...

摘要: 自适应波束形成器对模型失配与运动干扰非常敏感，特别是训练数据中包含期望信号分量时，较小的系统误差也会导致算法性能严重下降。该文提出一种零陷展宽鲁棒自适应波束形成算法，通过重构和优化干扰加噪声协方差矩阵，并估计真实导向矢量来提高算法抗系统误差与运动干扰的鲁棒性。该算法还可以通过调整主瓣宽度来优化波束旁瓣。仿真实验验证了所提算法的正确性和有效性。 关键词: 信号处理 / 自适应波束形成器 零陷展宽 鲁棒性

Direction of arrival (DOA) estimation is great interest due to its wide applications in sonar, radar and many other areas. However, the near-field interference always presented received data, which may result degradation DOA estimation. An approach can suppress preserve far-field signal desired by using a spatial matrix filter proposed this paper some typical algorithms are adjusted match filtered data. Simulation results show that improve capability under inference efficiently.