雷达罩瞄准误差测量不确定度评定方法研究

雷达罩电性能测试系统是一种复杂的计量器具,需要对其检测结果的不确定度进行评定,以前在这方面几乎没有开展工作。以雷达罩电子定标法为例,对影响瞄准误差测试结果的主要因素进行了分析,确定了不确定度分量。采用A 类或B 类评定方法,对每个分量的标准不确定度进行了分析计算。研究了不确定度分量之间的相关性,并对合成标准不确定度和扩展不确定度进行了计算。该方法也可用于雷达罩传输效率、方向图畸变和功率反射等电性能参数测量不确定度的评定。     

炮用象限仪角度测量不确定度的评定方法

竞争择优任务要求炮用象限仪角度测量结果给出不确定度,以便于不同行业领域的理解、交流和比对。在评定测量不确定度的过程中,鉴于实际工程测量样本量小而难以实施A类评定的问题,提出用实验室校准过程近似实际测量过程,利用历史校准数据和线性回归方法,建立了基于统计过程控制技术的A类评定方法,以某型炮用象限仪的历史校准数据并结合MATLAB工具验证该方法可行。用测量不确定传递率法得到了该型炮用象限仪测量范围内任意角度上的扩展不确定度曲线,并用蒙特卡洛法对其进行了验证。     

滑翔制导炮弹非线性自抗扰过载控制器设计

针对滑翔制导炮弹控制系统存在不确定内、外扰动以及舵偏指令响应滞后情况下的过载跟踪问题,基于自抗扰控制技术,设计了非线性自抗扰过载跟踪控制器。该控制器结构简单,计算量小,需调整参数少。数值仿真结果表明：该自抗扰过载控制器可在强扰动和舵机响应延迟的情况下,使得输出过载精确有效地跟踪过载指令,具备良好的抗干扰能力;并且舵控指令从0缓慢变化,有效地减缓了舵机的控制负担。该控制器对较大范围内的气动参数和舵机时间常数的摄动具备较强的适应性和鲁棒性,可为滑翔制导炮弹的控制系统设计提供一定的参考依据。     

Value‐centric framework and pareto optimality for design and acquisition of communication satellites

Investments in space systems are substantial, indivisible, and irreversible, characteristics of high‐risk investments. Traditional approaches to system design, acquisition, and risk mitigation are derived from a cost‐centric mindset, and as such they incorporate little information about the value of the spacecraft to its stakeholders. These traditional approaches are appropriate in stable environments. However, the current technical and economic conditions are distinctly uncertain and rapidly changing. Consequently, these traditional approaches have to be revisited and adapted to the current context. We propose that in uncertain environments, decision‐making with respect to design and acquisition choices should be value‐based. We develop a value‐centric framework, analytical tools, and an illustrative numerical example for communication satellites. Our two proposed metrics for decision‐making are the system's expected value and value uncertainty. Expected value is calculated as the expected NPV of the satellite. The cash inflow is calculated as a function of the satellite loading, its transponder pricing, and market demand. The cash outflows are the various costs for owning and operating the satellite. Value uncertainty emerges due to uncertainties in the various cash flow streams, in particular because of market conditions. We propagate market uncertainty through Monte Carlo simulation, and translate it into value uncertainty for the satellite. The end result is a portfolio of Pareto‐optimal satellite design alternatives. By using value and value uncertainty as decision metrics in the down‐selection process, decision‐makers draw on more information about the system in its environment, and in making value‐based design and acquisition choices, they ultimately make more informed and better choices. Copyright © 2009 John Wiley & Sons, Ltd.     

TS9980测试系统S1测量不确定度的评定

文章从对比介绍随机误差与系统误差开始,引入测量不确定度的概念,并分析了测量误差与测量不确定度的区别.文章以EMC测试中的抗扰度测试为背景,详细进行了一次音视频产品抗扰度特性测试的不确定度分析.说明了测量不确定度在测量结果的表达中具有重要的作用.     

Reducing the effects of the noise uncertainty in energy detectors for cognitive radio networks

Because of its ease of implementation and minimum requirements about the primary signals' information, energy detection is broadly considered for signal detection in spectrum sensing algorithms. However, the noise uncertainty phenomenon, caused by the random variations in the noise power, degrades the performance of an energy detector, particularly when the signal‐to‐noise ratio (SNR) is low. In this work, we propose to reduce the negative effects of the noise uncertainty in the performance of an energy detector by dynamically adapting its detection threshold to the noise conditions experienced at each sensing epoch. The noise power is estimated from the received signal samples using an algorithm based on a high‐pass filters bank and median filtering. With our proposal, it is possible to maintain a constant and low false alarm rate in the presence of noise uncertainty, without increasing the probability of misdetection, even in the low SNR regime, and without increasing the number of samples considered for spectrum sensing. Copyright © 2014 John Wiley & Sons, Ltd.     

IEC浪涌测试标准新发展

浪涌测试是衡量产品电磁兼容性能的重要实验项目,该文通过对新版IEC61000—4—577B／674MCD2012文稿的分析,总结了IEC浪涌标准在波形的定义、耦合去耦网络、测试方法、不确定度估算等方面的新情况。     

EMC辐射骚扰场强的测量不确定度分析与评定

辐射骚扰场强是EMC测量的重要技术指标，在给出其测量结果的同时还必须给出测量不确定度。本文在介绍测量不确定度与误差基本概念的基础上，分析了辐射骚扰场强的测量不确定度的来源，确定其评定方法，并给出评定结果。     

MPL探测气溶胶误差的数值模拟计算研究

微脉冲激光雷达(micropu lse lidar,MPL)是一种新型的激光雷达系统。通过对其探测的大气气溶胶后向散射比和后向散射系数进行误差的数值模拟计算,分析了误差源及其不确定性,给出了误差数值模拟计算的方法。较为详细地分析和讨论了各误差源对大气气溶胶后向散射比和后向散射系数的影响,为进一步提高微脉冲激光雷达的测量精度提供了可靠的理论依据。