This observation occurred during a solar occultation , where the sun passed directly behind saturn and left cassini in saturn ' s shadow with brilliantly backlit rings 此次观测是当太阳正从土星后面经过而卡西尼号则处在土星的阴影中时进行的，在背光中光环显得很明亮。
2 . the inversion techniques of occultation data are described and discussed in details . taken gps / met observations as examples , the atmospheric parameters profiles are retrieved accurately 5 、利用人工神经网络方法同化电离层掩星观测数据,建立经验电离层模式,并应用之做短期的电离层预报。
Radio occultation technique for the earth ’ s atmospheric profiling , a new application of the global navigation satellite systems , is one of the most advanced space exploring techniques in the 21st century 地球大气无线电掩星观测技术是导航卫星应用新的生长点,是21世纪最先进的空间探测技术之一。
We can only detect the brightening of the occulted object by the " focusing " action of the gravitation lens . this effect is called microlensing . theoretically , einstein ring is formed whenever occultation happens 由于黑洞的强大引力，它会吞噬伴星上的物质，但这些物质并不会直堕进黑洞内，而是以螺旋状轨迹卷进去，形成一个旋涡盘，所以科学家称之为吸积盘。
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。
This technique can measure the profiles of meteorological fields of the neutral atmosphere and the electron densities of the ionosphere with high precision and high vertical resolutions . it can operate all - weather with long - term stabilities and global coverage . the global - distributed occultation data will have a huge promotion on the numerical weather prediction , climate and space weather researches 该技术可测量自地面到约800km高空的中性大气气象场和电离层电子密度剖面,具有全天候、长期稳定、高精度和高垂直分辨率等特点;该技术提供全球分布的资料,将对数值天气预报、气候研究和空间环境研究起极大的推动作用,在气象、空间、天文以及国防领域具有广泛的应用前景。
In the fifth part we describe the procedure of amalgamating target and put emphasis on the research of target tracking method , by building up the moving status of target we can solve the problem of occultation . - - filter is adopted to predict next position of target so we can reduce the range of seeking matched target 在跟踪过程中，着重针对多个运动目标遮掩的情况，设计了基于运动状态的识别和跟踪方法，并利用常系数的kalman滤波器对运动目标的位置进行预测，解决了目标遮挡情况下的识别和跟踪问题。
