随机起伏

一种新的射频脉冲波随机起伏测量系统的研究

A New System for Measuring the Random Fluctuation of Radar RF Pulse Wave

射频脉冲序列随机起伏的数据采集

Data Acquisition of Random Fluctuation Pulse Signal

首次将二维随机起伏表面应用到FDTD计算当中，给出了二维随机起伏表面的具体产生方法。

2D random rough surface is applied for the first time in FDTD simulation and the method how to generate the 2D surface is proposed .

组织中声速及密度的随机起伏引起超声散射，散射回波声压谱的均方值与组织中声速c、声速对温度的梯度dc／dt和组织的平均温度T等有关。

The fluctuations of ultrasound speed and tissue density cause the scattered wave . The average power spectrum of scattered wave is dependent on the ultrasound speed c , the ultrasound speed gradient with respect to temperature dc / dt alld the average temperature of tissue T.

高频电波在背景备向异性和不均匀的随机起伏电离层中的传播

HF wave propagation and scattering in turbulent ionosphere with anisotropic background

存在位相随机起伏时胶片的全息信息容量

The holographic information capacity of films in the existence of random phase fluctuations

增益及密度同时作随机起伏对流动型气体激光器光束质量的影响

Influence of simultaneous random fluctuations of gain and density on beam quality of flow-type gas lasers

本文对特种激光外差通信系统接收中频信号相位受大气湍流随机起伏进行了实验测试。

The phase fluctuations of receiving IF signal of special type laser heterodyne communication system are measured .

1928年，H.Nyquist指出随机起伏已是电子工程师必须重视的问题。

In 1928 , H. Nyquist showed that random fluctuations were a significant problem to electronic engineers .

射频脉间相位噪声经过微波检测电路、视频电路后变成随机起伏的视频脉冲信号。

The RF pulse-to-pulse phase noise through microwave test circuit becomes a VF pulse signal of random fluctuation .

具有随机起伏表面的正声速梯度浅海中的简正波声场

The normal-mode sound field in shallow water having a positive sound velocity gradient and a random fluctuation surface

对于光电倍增管，电视摄像管之类的电子探测器，噪声则表现为输出电流的随机起伏。

In electronic detectors such as photomultipliers and television tubes , noise manifests itself as random fluctuations in the output current .

在合理的简化条件下，推导了在增益及介质密度同时作随机起伏时使激光光束质量劣化的表达式。

Under rational simplification , the expression for the beam quality deterioration by simultaneous random flutuations of gain and density is given .

日动态多为随机起伏型，但在5口井发现有水温潮汐，绝大多数井中存在阶变或脉冲等。

The daily behaviors are mostly fluctuate types , but 5 wells have tidal effects and most wells posses stepwise or pulsed changes .

通过高速相机测量位移，利用卡尔曼滤波计算速度的方法，解决了雷射脉冲瞬间作用时速度随机起伏大和计算困难的问题。

From the proposed testing and calculation method , the problem of velocity random fluctuating phenomenon owing to test data fluctuating is resolved .

本文讨论了背景为各向异性、不均匀的随机起伏电离层中高频电波的传播和散射问题。

The study of HF wave propagation and scattering in random turbulent ionosphere with anisotropic and inhomogeneous background is presented in this paper .

大气湍流对光波传播的影响主要是由于大气随机起伏的湍流引起折射率的随机起伏，破坏了光波的相干性。

Random fluctuation of turbulence brings random fluctuation of refractive index and makes atmosphere become a random fluctuation medium , which destroys the coherence of light-wave .

然而，水声信道的随机起伏、时空频变的多途特征使水声通信技术成为当代最为复杂的通信技术之一。

Because of random variability in time space frequency and severe multipath channels , underwater acoustic communication technology becomes one of the most complex communication technology .

根据线性滤波器模型的基本原理，提出了一种改进的基于高阶滤波器的随机起伏海面仿真方法。

Employing the fundamental principle of linear filter model , an improved simulation method is developed based on a high-order filter model for randomly undulatory sea surface .

水下声信道是一个多途传播丰富、随机起伏剧烈的窄带时-空-频变信道，这些特性成为水下高速率、高可靠通信的主要障碍。

Underwater acoustic channel is one of the most challenging channels for its space-time-frequency varying and frequency-selective characters . These features serve as the major obstacles to high-speed and reliable underwater communication .

例如在水声信号处理中，乘性噪声可以描述随机起伏对声波的影响，这一起伏可由介质（散射，内波，微结构），流向改变和目标散射引起。

For example , in underwater acoustic application , the multiplicative noise describes the effects acoustic waves due to the fluctuations caused by the medium , changing orientation and interference from scatters of the target .

基于脉冲回声探测的主动声引信识别水面舰船，随机起伏的波浪回声干扰是限制其可识别水面舰船最小吃水的主要因素。

For the active acoustic fuze for a torpedo on the basis of the distance measurement done by using acoustic pulses , the echo of a randomly undulating wave is a main disturbance to recognize a surface ship .

建立了激光散斑模型，模拟了高斯随机表面起伏产生的激光散斑场。

We have established the laser speckle model , and also simulated the laser speckle field produced by Gaussian random surface .

在波导中换能器随机摇摆对声场起伏的影响

On the effect of free swing of transducers in wave-guide on the fluctuation of received sound signal

假设粗糙表面为具有正态概率分布的平稳随机过程，研究了平面波在不平表面上的散射，求得了平面波在随机起伏表面上的统计平均反射系数，指出与随机表面空间相关的联系。

Assuming that the rough surface is a stationary process with a normal distribution , the scattering of a plane acoustic wave by this surface is studied . The statistical mean of the reflection coefficient and its relation to the correlation radius of the random surface have been discussed .

电离层中电子密度随机、快速的不均匀变化，会导致穿越电离层的无线电信号振幅、相位和偏振方向的快速随机起伏，即电离层闪烁。

Ionospheric scintillation is a rapid change in the amplitude and phase of a radio signal as it passes through small-scale plasma density irregularities in the ionosphere .