As it circles our planet , the changing position of the moon with respect to the sun causes our natural satellite to cycle through a series of phases : new , new crescent , first quarter , waxing gibbous , full , waning gibbous , last quarter , old crescent and back to new again 当月球进入地球的半影时，应该是半影食，但由于它的亮度减弱得很少，不易察觉，故不称为月食，所以月食只有月全食和月偏食两种。
The potential safety hazard of space debris and useless satellites to the normal operating satellites could not be overlooked . it is necessary to take practical measures to make space debris and useless satellites reentry into the earth ’ s atmosphere 空间碎片以及废弃卫星对在轨运行的航天器是一个不容忽视的重大安全隐患,因此需要采取一定的措施使空间碎片或废弃卫星脱离原轨道而进入大气层烧毁掉。
These institutions have made use of both domestic and foreign remote - sensing satellites to carry out application studies in weather forecasting , territorial survey , agricultural output assessment , forest survey , natural disaster monitoring , maritime forecasting , urban planning and mapping 这些专业机构利用国内外遥感卫星开展了气象预报、国土普查、作物估产、森林调查、灾害监测、环境保护、海洋预报、城市规划和地图测绘等多方面、多领域的应用研究工作。
The scientists used a variety of data from satellites to track the speed of the glaciers before and after the collapse of larsen b . in one study , ted scambos of the national snow and ice data center in boulder , us , analysed five images taken by the landsat 7 satellite between january 2000 and february 2003 在一项研究中，美国国家冰雪数据中心位于博尔德市的特德斯坎博斯对美国地球资源探测卫星7号在2000年1月和2003年2月之间拍摄的五幅图像进行了分析。
And then , according to the kind of satellite and the requirements for geodetic and astrometric study and the geometry of gnss ( gps , galileo ) satellite to track the space vlbi satellite , the six keplerian elements of chinese space vlbi satellite ( test - svlbi ) are selected and determined 根据卫星轨道的分类、大地测量和天体测量对空间vlbi卫星的要求,以及gnss ( gps和galileo )卫星对空间vlbi卫星跟踪观测的几何条件而设计了我国空间vlbi卫星的六个轨道根数。
Distant medical services make interactive multi - media communication a reality by using modern communication technologies such as satellite to transmit electronic medical data including high - resolution images , ecg , voices and medical records from where a patient is to an expert who sits in front of a terminal in a hospital many miles away , a process that enables medical experts to provide timely diagnosis and treatment to cure diseases and save lives 远程医疗系统是通过利用许多通信技术，包括卫星，将电子医务数据如高清晰度图像、心电图、声音和病历资料等从病人所在地传送到远端医院医疗专家面前，实现了交互式多媒体通信，然后由医疗专家提出治疗意见和方法，达到治病救人的目的。
This dissertation introduces a kind of car navigation system which use inertial navigation equipments and gps navigation satellite to realize the real time orientation . this instrument for navigation can measure informations of vehicle instantaneously , such as altitude , longitude , latitude and display these information on tft lcd 本文介绍了一种利用车载惯性导航设备和gps导航卫星进行车辆实时定位的导航系统，该导航仪用于实时测量车辆的经纬度、高度等数据信息，并显示在外挂的tft液晶屏上。
Using data from ships , planes and satellites to study asia ' s haze during the northern winter months of 1995 to 2000 , scientists discovered not only that the smog cut sunlight , heating the atmosphere , but also that it created acid rain , a serious threat to crops and trees , as well as contaminating oceans and hurting agriculture 科学家们通过飞船飞机和卫星发回的1995年到2000年亚洲北部冬季期间的有关气象数据来对亚洲脏雾进行分析研究。研究发现，这片烟雾不仅仅能阻断阳光射入和引起大气层升温，而且还能够引起酸雨，这就对农作物和树木构成了威胁，而且还会对海洋造成污染，对农业造成伤害。
The method to design global coverage satellite constellation is discussed with the help of simulation analysis . the dissertation presents algorithms of global coverage and regional coverage for satellites to observe space , and these algorithms are proved with the help of aggregate . space - based infrared system are conjectured and analyzed based on these algorithms 卫星星座是多颗卫星进行协同的主要形式，本文讨论了仿真与解析相结合的全球覆盖卫星星座的设计方法，同时提出了卫星星座空间观测的区域覆盖与全球覆盖判别算法，并进行了证明，在此基础上，对美国天基红外系统（ sbirs ）进行了性能推测与分析。
