However , this does not take into account visual comfort ; for comfortable viewing of the sun , a filter with a luminous transmittance of 0 . 0003 % ( shade number 14 ) is often preferable 然而,以上的计算并未考虑到观测时的舒适程度.在考虑舒适程度后,建议使用0 . 0003 %透光率(相当于14号密度)的滤镜作太阳观测
On 9 september , we also took the opportunity to test out emergency communication facilities at amo , and to exercise on our manual observations which would be required in the event of failure of weather sensors 在九月九日，我们也测试机场气象所的紧急通讯设施及演习当气象探测装置失灵时要作人手操作观测时的情况。
On 9 september , we also took the opportunity to test out emergency communication facilities at amo , and to exercise on our manual observations which would be required in the event of failure of weather sensors 在九月九日，我们也测试机场气象所的紧急通讯设施及演习当气象探测装置失灵时要作人手操作观测时的情况。
System with input delay arise in many engineering fields such as aircraftcontrol and network control . in this thesis , we considered two problems which are discussed for discrete - time case and continuous - time case , respectively 本文研究了两个问题,观测时滞的h输出反馈控制问题与多输入时滞的跟踪控制问题,每个问题都分别考虑了离散与连续系统。
The intrinsic time delayed properties of system may lead to measurementdelays , but the time delays in measurement equations of this thesis are alwaysresulted from the signal transmission processing of the sensors which is used toobserve 观测时滞可能是由系统的固有时滞特性引起的,而本文中观测方程中出现时滞则往往是由于用于观测的传感器在信号传输过程中导致的滞后系统。
Secondly , aiming at measurement being only from one satellite and the ekf being not stable , the measure equation is improved . transforming the form of angle measurements by the imaging theory , linearization of measure equation is realized by fake data of measurement . parameter of ballistic missile trajectory is estimated by using ekf , and the simulation shows that the unstabilization problem of ekf with true measurements is solved by using ekf with fake measurements 在仅有一颗预警卫星能够观测到目标的情况下,针对扩展卡尔曼滤波不稳定的问题,对观测方程进行改进,利用光学成像系统的原理,将测量量进行变换,并利用新生成的伪测量量使测量方程线性化,再利用扩展卡尔曼滤波算法对目标的弹道参数进行估计,最后,通过数学仿真来证明利用伪测量量的扩展卡尔曼滤波解决了单颗卫星观测时利用真实测量量的扩展卡尔曼滤波不稳定的问题。
Originating airport name , metar speci issue time , wind direction speed gust , wind direction variation , visibility , runway visual range , weather during time of observation , cloud , air temperature dew - point , qnh pressure measured at airport with adjustment made to suit aeronautical use , weather during the past hour but not at time of observation , wind shear information , trend - type landing forecast 发出资料的机场名称发出metar speci的时间风向风速阵风风向转变能见度跑道视程观测时的天气云层气温露点qnh在机场录得的气压，经调整以配合航空用途过去一小时但非观测时的天气风切变资料飞机降落用的趋势预测。
With the three - dimensional ray - tracing program , the simulation of leo - gps occultation is given . the radio path of occultation observation is simulated , and then the excess phase delay is calculated . this work can be used for studying the effects of the neutral atmosphere and ionosphere on the occultation observations and evaluating the performance of the inversion techniques 本文介绍了无线电掩星技术的发展状况和基本原理,围绕无线电掩星技术及其应用研究展开诸多研究和探讨,主要工作内容如下: 1 、利用全球三维射线追踪程序,开展leo - gps掩星观测的模拟研究,以计算掩星观测时电波传播路径、计算大气引起的附加相位时延等。
Speci is special weather report issued when there is significant deterioration or improvement in airport weather conditions , such as significant changes of surface winds , visibility , cloud base height and occurrence of severe weather . the format of the speci report is similar to that of the metar and the elements used have the same meaning . the identifier metar or speci at the beginning of the weather report differentiates them 发出资料的机场名称、发出metarspeci的时间、风向风速阵风、风向转变、能见度、跑道视程、观测时的天气、云层、气温露点、 qnh (在机场录得的气压，经调整以配合航空用途) 、过去一小时(但非观测时)的天气、风切变资料、飞机降落用的趋势预测。
In the case of imaging reconnaissance satellite ( irs ) observing area target , different part of the target can be observed as different elevation is chosen . this situation brings an optimization problem : how to choose the elevation of every access to guarantee the maximal efficiency of the whole process 多颗成像侦察卫星在指定的时间段内对单个区域目标进行观测时,选择不同观测方案会产生不同的时间覆盖率与空间覆盖率效果,如何选定观测方案,使得观测活动能够更好的达到所需要的覆盖率效果是一个重大的优化问题。
