利用MATLAB实现图像处理与分析

本文通过对图像的均衡操作、二值图像的处理、小波去噪等实例，介绍了MATLAB进行图像处理和分析的实用方法与技巧，它对各种软钉包、进行图像处理和分析等，提供了高效便捷的方法。     

A two-step ionospheric modeling algorithm considering the impact of GLONASS pseudo-range inter-channel biases

The Global Navigation Satellite System presents a plausible and cost-effective way of computing the total electron content (TEC). But TEC estimated value could be seriously affected by the differential code biases (DCB) of frequency-dependent satellites and receivers. Unlike GPS and other satellite systems, GLONASS adopts a frequency-division multiplexing access mode to distinguish different satellites. This strategy leads to different wavelengths and inter-frequency biases (IFBs) for both pseudo-range and carrier phase observations, whose impacts are rarely considered in ionospheric modeling. We obtained observations from four groups of co-stations to analyze the characteristics of the GLONASS receiver P1P2 pseudo-range IFB with a double-difference method. The results showed that the GLONASS P1P2 pseudo-range IFB remained stable for a period of time and could catch up to several meters, which cannot be absorbed by the receiver DCB during ionospheric modeling. Given the characteristics of the GLONASS P1P2 pseudo-range IFB, we proposed a two-step ionosphere modeling method with the priori IFB information. The experimental analysis showed that the new algorithm can effectively eliminate the adverse effects on ionospheric model and hardware delay parameters estimation in different space environments. During high solar activity period, compared to the traditional GPS + GLONASS modeling algorithm, the absolute average deviation of TEC decreased from 2.17 to 2.07 TECu (TEC unit); simultaneously, the average RMS of GPS satellite DCB decreased from 0.225 to 0.219 ns, and the average deviation of GLONASS satellite DCB decreased from 0.253 to 0.113 ns with a great improvement in over 55%.     

GeoWebCache瓦片地图服务中间件研究

本文以GeoWebCache开源瓦片地图服务中间件为例,剖析其工作原理和系统结构,并与传统WMS( Web Map Service)进行了性能对比,实验结果表明采用GeoWebCache中间件比直接访问WMS服务的平均响应时间减少约36％最后,从瓦片空间索引,扩展机制及系统部署策略等三个方面给出了GeoWebCache...     

全要素地形图作为背景在规划业务系统中的应用与实现

全要素地形图中的地理信息准确、规范、丰富,地形图比例尺与规划深度和出图比例相一致,而且精度能满足规划要求。打散入库后的全要素地形图和规划审批人员习惯的"蓝晒图"效果一致,且更新及时、方便,具有较强的现势性,在规划编制、规划审批等各个业务环节中起到了重要作用。本文详细阐述了全要素地形图的处理、转换、入库和更新过程,并对过程中应注意的问题提出了自己的意见和建议。     

分数布朗运动的小波分析

给出了分数布朗运动的连续和离散小波分析,讨论了有关的性质,并将结果用于分维估值、分数布朗运动小波变换系数的相关性研究等方面。     

超文本电子地图集系统

介绍了超文本电子地图集系统HEAS的若干概念,分析了现有地理信息系统的优点和弱点,介绍了超文本电子地图集系统的特性和武测超文本电子地图集实验系统方面的研究成果。     

前方交会及光电高程导线在桥梁圆形立柱监理中的应用

根据对前方交会及光电高程导线的精度分析,对用前方交会及光电高程导线复核圆形立柱进行了探讨,并给出了工程实例验证.     

50 m天线轨道调整方法

介绍50m天线的工程概况以及全站仪、数字水准仪和合相水平仪在天线轨道调整中的应用,重点介绍轨道径向偏差和法向偏差测量方案的制定以及轨道调整的具体实施方法,对相关工程有一定的参考价值。     

地图代数的符号化方法

根据地学数据库中符号的定位数据和符号码，使用点阵符号库中的符号数据进行符号化，由此得出的图形美观，生动，河流具有粗细变化，该方法简洁通用，具备数据独立性和程序独立性。