| 1. | Semiconductor discrete device . detail specification for type cs203 gaas microwave low noise field effect transistor
半导体分立器件. cs203型砷化镓微波低噪声场效应晶体管详细规范 |
| 2. | But actually , the vector sensor ' s detection gain will be limited by the finite noise counteract for the existence of anisotropic component in the noise field
但实际中，由于噪声场中存在各向异性成分，噪声的声能流只能被有限抵消。 |
| 3. | In this paper , the self - adaptive filter , the wavelet transform and the fourier transform are used to detect the stationary and the non - stationary signal of underwater sound in anisotropic noise field
本文以各向异性噪声场为例，分别对声矢量信号中的声压、振速探讨应用自适应滤波、小波变换、短时傅里叶变换检测水声平稳和非平稳信号的应用效果。 |
| 4. | The results show that the self - adaptive filter can be used to detect line spectrum , the wavelet transform and the fourier transform can be used to detect the ship noise in modulating the anisotropic noise field
结果表明：自适应滤波对于各向异性噪声场中的线谱检测有良好的效果；而小波变换和短时傅里叶变换对各向异性噪声场中的舰船噪声调制信号检测有良好的效果。 |
| 5. | Wavelet transform , which developed in late 1980 ' s , is a new kind of time frequency analytic method . it has good localization characteristic in both time and frequency domain ; and has been applied for signal de - noising fields
小波变换是八十年代末发展起来的一种新的时频分析方法，它在时、频两域都具有良好的局部化特性；并且在信号去噪领域获得了广泛的应用。 |
| 6. | 5 ) based on the noise model with a centro - hermitian covariance matrix , a differential denoising bearing estimator is developed for coherently distributed sources in unknown noise fields . its accuracy and resolution performance is analyzed theoretically and numerically
5 )针对未知噪声环境中相干分布源的方向估计问题，提出了一种差分去噪估计器，并从理论和数值结果两个方面评价了它的精度和分辨率性能。 |
| 7. | In chapter 3 , we discuss the problem of doa estimation in the presence of spatially nonstationary noise fields . an estimate of the colored noise covariance matrix is firstly given . the received data for parameter estimation is then prewhitened using the estimated noise covariance , hence , overcoming the highly biased estimates . finally , adaptive beamforming with the modified weight is also performed . computer simulations show that the proposed method can completely remedy beam distortion . 3
在第三章讨论了一种在环境噪声为白噪声而阵元噪声为空间非平稳情况下的doa估计问题，给出了一种有效的估计阵元噪声功率的方法，进而利用估计的噪声协方差矩阵进行预处理而实现色噪声环境下的doa估计，理论分析和仿真结果均表明了本章提出的方法的有效性。 |
| 8. | The coherence analysis of the sound field using prssure and particle velocity combined processing was discussed . a new kind of combined sensor was used to gather the information of the sound field . the main idea of this paper is to seperate ambient noise field ， and the characteristics of it can be further studied . the coherence of a point source sound field was also analyzed to verify the validity of the approach
声场声压与振速的相干性是声压、振速信息联合处理的重要物理基础之一，本文对其进行了初步的分析.在新型组合传感器湖试的基础上，把环境噪声场分解为不相干的各向同性分量和相干的各向异性分量，初步分析环境噪声场的构成；同时对点源声场的相干性也进行了验证性的分析 |
| 9. | Meanwhile , motion compensation method is used for amfp to improve the localization effect . with strong interferes at surface , non - stationary noise field and mismatch environment , subspace motion compensation method and efficient amfp system frame are proposed and confirmed by simulation and real data
针对存在水面强干扰、非平稳噪声场和海洋环境参数失配的一般浅海复杂水声环境，提出了基于子空间分解的运动补偿算法和自适应匹配场定位的系统解决方案，并通过仿真数据和实验数据进行了验证。 |
