Local-linear-prediction in phase space is performed for the underwater acoustic target radiated noise. Relation curve of average prediction error versus neighboring points' number is calculated. The result is used...Local-linear-prediction in phase space is performed for the underwater acoustic target radiated noise. Relation curve of average prediction error versus neighboring points' number is calculated. The result is used in judging the nonlinearity of radiated noise time series, and obtaining the appropriate form and coefficients of predicting model. The line and continuous spectral component are predicted respectively. Choice of some model parameters minimizing the prediction error is also discussed.展开更多
Signal processing in phase space based on nonlinear dynamics theory is a new method for underwater acoustic signal processing. One key problem when analyzing actual acoustic signal in phase space is how to reduce the ...Signal processing in phase space based on nonlinear dynamics theory is a new method for underwater acoustic signal processing. One key problem when analyzing actual acoustic signal in phase space is how to reduce the noise and lower the embedding dimen- sion. In this paper, local-geometric-projection method is applied to obtain fow dimensional element from various target radiating noise and the derived phase portraits show obviously low dimensional attractors. Furthermore, attractor dimension and cross prediction error are used for classification. It concludes that combining these features representing the geometric and dynamical properties respectively shows effects in target classification.展开更多
由于水下环境的复杂性导致水声网络节点通常存在一定的漂移,从而引起网络节点自定位的不准确;又因为水下测距不准确导致TDOA测距中也存在一定的误差。以上两类前期噪声误差均会降低网络对目标定位时的精度。针对以上问题,本文提出一种...由于水下环境的复杂性导致水声网络节点通常存在一定的漂移,从而引起网络节点自定位的不准确;又因为水下测距不准确导致TDOA测距中也存在一定的误差。以上两类前期噪声误差均会降低网络对目标定位时的精度。针对以上问题,本文提出一种基于噪声向量模值最小的高精度水声网络TDOA目标定位方法。该方法利用LS(least-squares)算法得到目标定位的初值,通过考虑节点自定位误差和TDOA测距误差对算法精度的影响,经过一系列转换得到目标函数,使得上述两种前期噪声误差对定位精度的影响达到最小;根据初值及目标函数,采用模拟退火智能优化算法得到目标位置。仿真结果表明:与WLS(weighted least-squares)算法、CTLS(constrained total least-squares)算法相比较,本文算法定位精度高且前期误差对算法性能影响小,鲁棒性强。展开更多
基金The work was supported by the fund (2000JS24.4.1) from the State Key Lab on Ocean Acoustics andthe research fund of Ship Industry Fundamental Research.
文摘Local-linear-prediction in phase space is performed for the underwater acoustic target radiated noise. Relation curve of average prediction error versus neighboring points' number is calculated. The result is used in judging the nonlinearity of radiated noise time series, and obtaining the appropriate form and coefficients of predicting model. The line and continuous spectral component are predicted respectively. Choice of some model parameters minimizing the prediction error is also discussed.
文摘Signal processing in phase space based on nonlinear dynamics theory is a new method for underwater acoustic signal processing. One key problem when analyzing actual acoustic signal in phase space is how to reduce the noise and lower the embedding dimen- sion. In this paper, local-geometric-projection method is applied to obtain fow dimensional element from various target radiating noise and the derived phase portraits show obviously low dimensional attractors. Furthermore, attractor dimension and cross prediction error are used for classification. It concludes that combining these features representing the geometric and dynamical properties respectively shows effects in target classification.
文摘由于水下环境的复杂性导致水声网络节点通常存在一定的漂移,从而引起网络节点自定位的不准确;又因为水下测距不准确导致TDOA测距中也存在一定的误差。以上两类前期噪声误差均会降低网络对目标定位时的精度。针对以上问题,本文提出一种基于噪声向量模值最小的高精度水声网络TDOA目标定位方法。该方法利用LS(least-squares)算法得到目标定位的初值,通过考虑节点自定位误差和TDOA测距误差对算法精度的影响,经过一系列转换得到目标函数,使得上述两种前期噪声误差对定位精度的影响达到最小;根据初值及目标函数,采用模拟退火智能优化算法得到目标位置。仿真结果表明:与WLS(weighted least-squares)算法、CTLS(constrained total least-squares)算法相比较,本文算法定位精度高且前期误差对算法性能影响小,鲁棒性强。
