信噪比

To meet the needs, a novel low-noise fiber laser with compound cavity structure is designed. The stable single-mode operation is realized by using a transient self-written fiber grating, produced by the effect of saturable absorption within a section of unpumped erbium-doped fiber, as narrow band filter for mode selecting and linewidth squeezing. Through optical path modification, the spectral signal-to-noise ratio is better than 62 dB.

激光器采用复合腔结构，以掺铒光纤作为工作物质，通过在未被抽运的掺铒光纤中形成的瞬态自写入光纤光栅的窄带滤波特性进行选模和压窄线宽，产生稳定的单频激光输出；经过光路改进，激光输出光谱信噪比优于62 dB；利用光电负反馈电路，弛豫振荡峰下降了约25 dB，低频段强度噪声也大为改善，有效地抑制了光源的强度噪声。

A new system design based on the conception of SOC is also given. Processing and tracking algorithms. Put forward some IR image algorithms by analyzing the characteristics of IR image such as: low contrast、ununiformity、wide gray dynamic range.

在红外图像处理算法方面，分析了焦平面红外图像具有的低信噪比、宽图像动态范围及图像非均匀性等特性，结合实际硬件条件，提出了直方图归一化、去冗余灰度均衡、受限空域锐化、多帧平均等处理算法，在实际应用中取得良好效果。

Starting from the output signal-to-noise ratio of vibration tables, the basic requirements of background noise of the foundation are determined, then the dynamic analysis of the foundation for tables and a laser vibrometer, and the static analysis of the foundation for the laser vibrometer are done with finite element method.

首先以振动台台面输出信噪比为出发点，确定了超低频标准振动台基础噪声的基本要求；然后采用有限元分析的数值方法，分别对振动台基础与激光测振仪基础作动力学分析，再对激光测振仪基础作静力学分析。

Reducing the complexity of vector quantization is still a main problem. This paper presents a new algorithm of minimum distortion predicting vector quantization based on intraband and interband correlation. Here the whole distortion of the vector is predicted by the part distortion of the lower frequency coefficient components of vector, resulting in a reduction of 76 percent of complexity.

降低矢量量化器的复杂度一直是人们研究的一个主要问题，本文提出一种新的基于带间相关性的最小失真预测矢量量化算法，通过矢量中前面部分低频系数分量失真的计算去预测整个矢量的失真，编码复杂度降低了76％，而解码图像信噪比下降不到1dB。

Curves for the BER are obtained based on the derived SNR at the output of the equaliser.

误码率曲线的基础上得到的衍生的输出信噪比的扳平。

For the first time, we observe the polarization effect in two-core fiber interferometers, for which we give our analyses and explanations in the thesis. This effect can be used to improve the S/N ratio and the stability of the system. Meanwhile, we did experiments to measure strain within a deformed cantilever, and the results are in agreement with our theory.

本文分析探讨了双芯光纤应变干涉测量的基本原理，对实验系统及现象进行了较为详细的分析，首次发现并验证了双芯光纤干涉中存在的偏振效应，提出了提高系统信噪比和稳定性的新方法；同时进行了一些实验研究，取得了与理论基本一致的结果。

It is a significant for the development of the geoscience study to solve the earth surface effect and to improve ratio of signal to noise in the heavily ambient noise with speed industrialization and citifying.

其目的是为了解决地球的表面效应和人类社会高度发展的城市化、工业化、现代化带来的噪音干扰，提高信噪比，推进现代地球物理观测与研究。

Experiments on synthetic images with low signal-to-noise ratio and scene images show good performance and robustness of the approach, especially it's capabilities of capturing the discontinuous boundary and moving snakes into boundary concavities.

对人工合成的低信噪比图像及景物图像的实验表明本文方法具有很好的性能及鲁棒性，特别是在处理目标边缘不连续及有凹形边缘时更显示了其优越的性能。

Experiments on synthetic images with low signal-to-noise ratio images and nature images show good performmance and robust of the approach, especially it's capable to capture the discontinuous boundary and move snakes into boundary concavities.

对人工合成的低信噪比图像及自然图像的实验表明，本文方法性能良好，工作稳定，具有较强的处理边缘不连续及进入凹形边缘能力。

For example, signal-to-noise performance degrades as a result of reduced signal swing.

例如，信噪比由于信号摆幅的减少而降低。

Finally, according to market conditions and market products this article paper analyzes the trends in the development of camera technology, and designs a color night vision camera.

最后根据市场情况和市面上产品的情况分析了摄像机技术的发展趋势，并设计了一款彩色夜视摄像机。

Only person height weeds and the fierce looks stone idles were there.

只有半人深的荒草和龇牙咧嘴的神像。