WGS-84与地方坐标系转换参数的优化选择

针对GPS动态RTK测量中WGS-84与本地坐标系转换参数的选择进行研究。首先根据稳健估计方法对控制点的精度进行评定,剔除含有粗差的控制点。然后利用概率统计理论对转换参数的优化选择进行分析,确定转换参数最优值。为便于实际应用,编写了转换参数优化选择软件,并将此软件的计算结果应用到实践中,取得较好结果,为证明该方法的可行性提供可靠依据。     

苏通大桥钢箱梁制造几何控制三维高精度基准网测设

本文详细介绍了对苏通大桥主桥钢箱梁制造几何控制三维高精度基准网的测设，通过实际工程的实施对高精度三维基准网的方案设计和精度控制进行了有效的探索。     

用可见光与红外云图资料综合作降雨量估算的试验

利用红外和可见光云图亮温资料估算单站降水量级,结果发现红外和可见光云图结合估算降水量效果比单用红外云图效果要好,大雨的空报率明显降低。     

Some foundation stability problems of the railway bridge over the Mala Rijeka

SummarySome Foundation Stability Problems of the Railway Bridge over the Mala Rijeka The authors presented an outlay of problems occurring in estimating the stability of rocky slopes loaded by large vertical forces. General attitudes, kept by the authors during the stability analysis for an actual case — foundation of piers No. 3 and 4 of the railway bridge across the Mala Rijeka, are also presented. The results of calculation as well as the advantages of the approach applied are outlined in the paper. Finally, general conclusions are drawn regarding the method to be kept in solving the stability of slopes loaded by large artificial loading.With 7 Figures     

广西山地风能资源开发利用可行性分析——以大容山为例

利用大容山自动观测站2004年8月～2006年7月气象观测资料和容县气象站1958～2006年7月测风资料,对大容山的风能资源各参数进行了详细计算和分析,并结合预选风电场的地形地貌、交通运输、联网条件、环境保护等状况对大容山风能资源开发利用进行了可行性分析评价.结果表明：大容山年平均风速为7.2m/s,年平均风功率密度为390.8W/m^2,其风能资源丰富,且交通运输、联网、工程地质等条件较好,可选择在坡度较小的山头或山腰建设风电场,预选风电场可布置750kW的风机45台,总装机容量约为34MW.     

平差系统模型误差补偿的配置法

利用大地测量数据分析地壳形变所建立的平差系统，不可避免地存在模型误差。给出了估计模型偏差的带权均方误差公式，提出了模型误差的识别、先验协方差的确定以及用最小二乘配置法对平差系统模型误差的补偿方法。     

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????????Helmert????????????Vondrak????????????HVF??????????????GPS??·??Ч????о????????????????????????????÷???????????Vondrak?????????????????????????????????Ч????????????????е????????????????÷????????·????????????GPS??·??Ч?????????????????????Ч????????·??Ч??????????????????GPS??λ?????     

Spatiotemporal patterns of road network and road development priority in three parallel rivers region in Yunnan, China: An evaluation based on modified kernel distance estimate

Road network is a critical component of public infrastructure,and the supporting system of social and economic development.Based on a modified kernel density estimate(KDE)algorithm,this study evaluated the road service capacity provided by a road network composed of multi-level roads(i.e.national,provincial,county and rural roads),by taking account of the differences of effect extent and intensity for roads of different levels.Summarized at town scale,the population burden and the annual rural economic income of unit road service capacity were used as the surrogates of social and economic demands for road service.This method was applied to the road network of the Three Parallel River Region,the northwestern Yunnan Province,China to evaluate the development of road network in this region.In results,the total road length of this region in 2005 was 3.70×104km,and the length ratio between national,provincial,county and rural roads was 1∶2∶8∶47.From 1989 to 2005,the regional road service capacity increased by 13.1%,of which the contributions from the national,provincial,county and rural roads were 11.1%,19.4%,22.6%,and 67.8%,respectively,revealing the effect of′All Village Accessible′policy of road development in the mountainous regions in the last decade.The spatial patterns of population burden and economic requirement of unit road service suggested that the areas farther away from the national and provincial roads have higher road development priority(RDP).Based on the modified KDE model and the framework of RDP evaluation,this study provided a useful approach for developing an optimal plan of road development at regional scale.     

稳健的多基线SAR干涉相位估计

针对传统多基线合成孔径雷达干涉相位估计方法存在稳健性不高、适应性不强的问题,该文提出一种稳健的多基线合成孔径雷达干涉相位估计方法。利用最大似然频率估计准则从最短基线干涉图中提取每一复像元随基线变化频率的粗略估计值,并把提取的粗略频率通过共轭复乘补偿给相应的抽样复干涉信号,来降低抽样复干涉信号频率,避免了干涉基线间隔过大导致的抽样复干涉信号频谱混叠现象,从而克服了干涉基线间隔对长基线干涉相位估计精度的限制。实验结果表明,该方法不受干涉基线间隔的限制,能较为精确地获得长基线干涉相位估计值,对多基线干涉合成孔径雷达技术应用拓展以及高精度地理信息系统构建等具有参考价值。     

基于聚合点的网络多媒体业务拥塞控制

当前广泛开展的网络多媒体业务都存在不同程度的服务不稳定情况,其原因是架构于网络上的多媒体业务缺乏整体有效的网络控制机制.基于研究提出了一种基于聚合点的拥塞控制方法,能对网络多媒体业务进行有效的拥塞控制.与现有业务实施机制相比,该方案实现简单,能更有效保证业务的开展.