以1954年北京坐标为起算对GPS基线网平差的影响

本文分析了以1954年北京坐标为起算对GPS基线网平差的影响，并结合实例，得出了一些结论。     

峨眉宝光研究之一——宝光机理的综合研究

通过对宝光形成思路的追索，否定“冰晶云不可能出现宝光”的看法，综合考虑了不同条件下出现的宝光应遵循不同的形成机理。指出水云和冰晶云都能出现宝光，而冰晶云上宝光的伴生光象不是主虹，而是对日晕。     

城北高架点源对西湖风景区影响的研究

运用高斯扩散模式和实测扩散参数，计算了杭州市城北工业区几个高架点源排放的大气污染物对西湖风景区的影响及其时空分布。结果表明，在一定的气象条件下，城市高架源排放的二氧化硫等大气污染物对西湖风景区空气质量有影响。控制和减少城北高架源的排放有利于西湖风景区空气质量的改善。     

Rock magnetic properties of Nihewan sediments at Xujiayao

Rock magnetic measurements of Nihewan sediments from Xujiayao section demonstrate that magnetite, hematite and maghemite are dominant remanent magnetization carriers. Monitoring the variations of magnetic susceptibility (MS) and saturating isothermal remanent magnetization (SIRM) at low temperature are the attractive ways of detecting the presence of magnetite, maghemitization and superparamagnetic grain sizes. Low-temperature MS investigations suggest that susceptibility enhancement for Xujiayao samples is mainly due to the remarkable presence of SD/MD magnetite to some degree though some magnetite grains have been partially oxidized at some depths. It is tentatively concluded that both SD/MD magnetite and hematite are of detrital origin and carry a characteristic remanent magnetization (ChRM), whereas maghemite can be attributed to be chemical origin, overprinting a reversed polarity component of Matuyama age.     

Sub-Daily Earth Rotation Parameters and the International GPS Service Orbit/Clock Solution Products

Tidally induced sub-daily Earth Rotation Parameters (ERP) variations, when not properly accounted for, can cause apparent orbit and ERP rate errors, which can significantly exceed the IGS solution errors. All International GPS Service (IGS) Analysis Centers currently apply the conventional sub-daily ERP model in their transformations from ITRF (International Terrestrial Reference Frame) to ICRF (International Celestial Reference Frame), both of which are used for IGS global analyses. However, some IGS Analysis Centers did not apply the sub-daily ERP model when transforming ICRF orbit solutions to ITRF, which is used for IGS orbit/clock products. This transformation inconsistency can cause significant orbit RMS differences that could exceed the 5-cm level. Independent ERP rate solutions are sensitive even to small errors in the sub-daily ERP model, and can be used to verify the sub-daily ERP model at, or below 0.1 mas/day precision level.The Precise Point Positioning (PPP) via precise station position solutions with the IGS orbit/clock combined products, provides an ideal interface to access the IGS realization of ITRF. PPP also yields precise station clock and tropospheric zenith delays (TZD) solutions, all at the sub-cm precision level. However, when using IGS orbit/clock products it is important that the same convention be used with respect to sub-daily ERP. Otherwise, the solutions of station navigation positions, station clocks and TZD's will be affected by significant errors that could exceed the 1-cm level.     

隧道工程GPS控制网的基准设计与数据处理

在布设隧道工程GPS控制网过程中，根据工程具体要求，需对工程GPS控制网进行基准设计，有的工程要求边长投影到测区平均高程面上，应对起算数据进行处理。有的工程要求采用一点一方位为控制网起算，以保证GPS网内符合精度不受损失。     

关于测设椭圆曲线的探讨

四心圆法测设椭圆曲线会造成点位偏移，图形变形。本文借助计算机，利用累加法，解决了以弧长为已知量计算椭圆曲线坐标的问题。     

矢量曲线的特征点提取

讨论了矢量曲线数据压缩的问题，介绍了Douglas-Peucker法并指出了其优缺点。提出了一种改进的Douglas-Peucker法，使速度有很大提高。还提出了一种新的方法－逐点前进法。试验表明，新方法比前述方法的保真度要好，曲线起伏变化大时速度大大快于前者。     

大尺度电离层行扰的GPS观测

利用日本境内的高空间分辨率的双频GPS台站资料,观测研究了发生于2000年7月中旬太阳强活动期间的一次大尺度电离层行扰. 结果表明:在7月15日11:00UT-1:00UT期间观测区域的电离层中出现了大尺度电离层行扰. 在15:00UT之前,扰动周期为2h左右,在15:00UT以后,扰动周期为1h左右;总电子含量扰动幅度的变化范围约为1-2TECU;通过对15:00-17:00UT之间总电子含量扰动曲线同相位点的分析,发现这期间的电离层行扰的扰动速度约为600-700m/s,扰动波长在2200km左右,扰动传播的方向几乎沿着经线从高纬向低纬传播. 该行扰与此次强太阳活动有直接的关系,因其发生在7月15日的磁暴急始之前数小时,因此与磁暴本身没有因果关系,应与磁暴之前先期到达地球空间的高能质子流有关.     

气象要素与云南震区最大震级的统计相关分析

根据地震活动与气象要素之间的密切关系 ,采用大量气象资料选取预报因子 ,建立逐步回归方程 ,将数理统计理论应用于地震预报 ,对中国云南 5个地震分区分上、下半年做出了最大震级预报 ,其置信度达到特别显著水平