GPS测量的中性大气折射改正的研究

中性大气对ＧＰＳ信号的折射影响是ＧＰＳ测量的重要误差源之一。测量定位的垂直分量精度的提高,受到中性大气延迟改正程度很强制约。     

结构瞬时开闭环最优控制算法中的迟时研究

本文运用四阶Ｒｕｎｇｅ－Ｋｕｔｔａ法建立了在迟时情况下结构状态方程的离散形式,采用瞬时控制开闭环最优控制算法对开环、闭环和开闭环控制中迟时的影响进行研究,并根据闭环控制的原理提出了迟时补偿算法,以减小迟时的影响。     

First complementary observations by ionospheric tomography, the EISCAT Svalbard radar and the CUTLASS HF radar

Experimental results are presented from ionospheric tomography, the EISCAT Svalbard radar and the CUTLASS HF radar. Tomographic measurements on 10 October 1996, showing a narrow, field-aligned enhancement in electron density in the post-noon sector of the dayside auroral zone, are related to a temporal increase in the plasma concentration observed by the incoherent scatter radar in the region where the HF radar indicated a low velocity sunwards convection. The results demonstrate the complementary nature of these three instruments for polar-cap ionospheric studies.     

Algorithm of the problem of simulating the total wave field of the geomagnetic pulsation signal within the ionospheric transition layer

Summary This supplement to paper by Prikner and Vagner (1991) describes the optimum algorithm for the automated computer program of numerical simulation of the total wave field anywhere within the ionospheric filter. The matrix method of thin layers in an inhomogeneous, anisotropic and dissipative ionosphere has been applied. The application of this method enables in situ measurements of geomagnetic pulsations in the ionosphere to be compared with the results of the numerical simulation.     

Coupling processes at the magnetopause

This review covers several aspects of magnetopause research during the two-year period from mid-1991 to mid-1993. It focusses upon three topics which received renewed attention: the structure of the steady-state magnetopause, the origin of the transient events which are superimposed upon it, and the cause of transient signatures observed by high-latitude dayside ground magnetometers. Case and statistical studies defined the relatively unknown characteristics of the magnetosheath plasma layers lying outside the magnetopause, while theoretical studies provided alternative explanations for the presence of magnetosheath plasma within the LLBL. Evidence was presented for a steady transition from magnetosheath to magnetospheric plasma parameters. Detailed studies described the plasma, energetic particle, and magnetic field characteristics of transient events in the outer dayside magnetosphere, and multipoint studies provided important new information concerning the ionospheric response to sudden changes in solar wind parameters. This review emphasizes the competing explanations which have been advanced to explain these phenomena.     

与地磁急始相伴的电离层暂态振荡

分析了从１９８５年９月至１９９２年１２月共１１５次急始型磁暴期间武昌多普勒台阵观测到的电离层暂态振荡（ＳＩＯ）．这种与地磁ＳＣ相伴的ＳＩＯ可分成ＳＣＦ（＋，－），ＳＣＦ（－，＋），ＳＣＦ（＋）与ＳＣＦ（－）几种类型．分析发现，伴随地磁急始在Ｆ区总是存在突发电离层暂态振荡，除非电波被吸收、穿透、被Ｅ５屏蔽，以致Ｆ区无反射回波或在反射区电离密度的高度梯度特别大，使多普勒频率很小在多普勒图上显示不出来．通常ＳＣＦ（＋，－）发生在白天，而ＳＣＦ（－，＋）发生在晚上．ＳＩＯ与地磁急始有很好的对应关系．     

浙江省近百年气温变化研究

利用浙江省近百年气温等级资料，分析全省冬季、夏季和全年气温变化，发现浙江省年气温变化总趋势与北半球、全国比较一致，但年气温上升、下降的时间比北半球、全国年气温变化有滞后现象。冬季最低气温升高，是暖冬的主要特征，夏季极端最高气温天数明显减少，是凉夏的主要特征。