信噪比

And images processed with the incorrect parameters will be worsened. This paper analyses the effect of SNR on autofocus and proposes an adaptive filter in SAR azimuth subsampling to keep SNR as high as possible, so that the performance of autofocus can be improved and higher image quality achieved.

该文分析了信噪比对自聚焦的影响，提出利用自适应滤波器来做方位向预滤波和降采样，在降低采样率的同时，保持原始图像的信噪比，再经有效的自动聚焦算法，得到较准确的多普勒参数估计值，从而获取高分辨率SAR图像。

It is more appropriate for narrow telephonic speech.

该算法突出的优点是适应的信噪比动态范围较宽，即使信噪比只有3.5dB，也能准确地检测到边缘时间点。

To aim at parameter estimation of signal to noise ratio and high variance in low SNR based on time frequency distribution, this paper proposed a novel algorithm based on multimodal particle swarm optimization.

针对基于时频分布的参数估计存在信噪比阈值和低信噪比下方差大的问题，提出了一种基于多峰优化粒子群算法的跳频信号参数估计新算法。

The algorithm s performance has been evaluated by simulating different types of band-limited digital signals corrupted by white Gaus...

计算机仿真表明：当噪声采用高斯白噪声，并且信噪比大于15dB时，识别率高于96%；当信噪比不低于10dB时，识别率不低于90%。

The unflatness of amplified spontaneous emission noise and its impacts imposed on the performance of the off-center narrow filter polarization-nulling method when monitoring the in-band optical signal-to-noise ratio of dense wavelength division multiplexing system are analyzed, and a modified method by introducing an unflat factor in the calculation of OSNR is proposed.

分析了累积自发辐射噪声的非平坦特性，在已有窄带离心偏振置零法测量波分复用系统中带内光信噪比的基础上，分析该方法在噪声非平坦条件下存在的问题，提出了在光信噪比的计算中引入修正因子。

In this paper, the noise sources of the EBCCD imaging system have been analyzed and a SNR model has been established. It shows that the SNR of output image is related not only to the input illuminance on the cathode but also to the spatial frequency of the input image. This has been proved by a series of experiment. Unperfectness of the detecting equation has been pointed out in this paper.

分析了电子轰击电荷耦合器件微光成像系统的噪声源，建立了系统的信噪比模型，指出了在微光成像系统本身的增益和量子效率等性能确定的条件下，成像系统输出图像信噪比不仅仅与输入面照度有关，还与输入图像的空间频率有关，并通过实验得到了证明，指出了经典的图像探测方程的不完善之处。

By comparing the error correction capability and stability under different signal-to-noise ratio conditions, and packet loss rate of the block code and the convolutional code in the same signal-to-noise ratio condition, the results show that correcting ability of this algorithm is better than that of other method under the low delay condition, and it can adapt the different network delay condition.

通过对比在不同的信噪比条件下卷积码的纠错能力和稳定性，以及在相同信噪比的情况下对分组码和卷积码的丢包率，说明本文算法的纠错能力在低解码延迟条件下好于现有方法，能适应不同的网络延迟条件。

In order to testify a pulse contrast measurement's dynamic range in a simple and clear way, this article uses a series of pulses with equal intervals and equal ratios of intensity as a criterion, which reflected from back surface of a 0°reflector, and first discuss the calibration of pulse contras measurement and verify it by experiments in the world.

为了从一个简洁明了的角度来判断信噪比测量系统的动态范围，本课题还将0°反射镜后表面的的二次反射光形成的等间隔、等比例衰减的脉冲序列作为基准，在国际上首先开展了信噪比测量系统的动态范围标定方法的研究工作，并通过实验加以验证。

The purpose of this thesis is not only to overcome multipath interference by spread spectrum but also to improve the performance of the system by employing RAKE receiver to recombine some multipath signals.

扩频技术特别是直接扩频技术也是对抗多径干扰的一种非常有效的技术，其中的RAKE接收技术不但能够抑制干扰；而且还能利用多径干扰的能量提高信噪比，极大的改善了系统的性能，并且扩频技术是现在唯一能工作在负信噪比条件下的通信技术，所以扩频技术在水声通信中的应用也越来越受到关注。

It was shown that the SNR of the RADS could be improved by using a microwave cavity with proper microwave field mode and high microwave filling factor, a rubidium spectrum lamp with high spectrum purity and a separated isotope filtering scheme in the physics package design. The performance of the rubidium atomic frequency standard could be improved by taking all these factors into consideration.

本文分析了微波腔的结构、铷光谱灯的光谱纯度和同位素滤光方案对信噪比的影响，指出采用模式优越、微波填充因子大的微波腔，光谱纯度高的铷光谱灯，用分离滤光方法进行同位素滤光，可以提高铷原子鉴频信号的信噪比，从而使铷频标的稳定度指标得到进一步改善。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。