GPS水准高程拟合模型的实践和探讨

本文介绍了确定GPS正常高的常用方法--GPS水准高程,通过工程实例,得出各种常用拟合方法的适用范围及精度情况,通过对各种拟合模型进行详尽的对比分析,选择有助于高程拟合时选择适宜的拟合函数,获得满意的精度和结果.     

An automatic cycle-slip processing method and its precision analysis

On the basis of analyzing and researching the current algorithms of cycle-slip detection and correction, a new method of cycle-slip detection and correction is put forward in this paper, that is, a reasonable cycle-slip detection condition and algorithm with corresponding program COMPRE (COMpass PRE-processing) to detect and correct cycle-slip automatically, compared with GIPSY and GAMIT software, for example, it is proved that this method is effective and credible to cycle-slip detection and correction in GPS data pre-processing.     

GPS测量船舶航速算法浅析

简要介绍了GPS的定位原理和测速原理,并对利用GPS测试船舶航速的四种算法进行了说明。在多个船舶航速算例的基础上,进行了分析并得出结论。     

Arctic sea-ice motion and its relation to pressure field

Daily Arctic sea-ice motion maps during the winter seasons (December–March) from December 1988 to March 2003 derived from NSCAT, QuikSCAT, SSM/I, and AMSRE data by a wavelet analysis method have been merged with those derived from buoy data. These merged sea-ice motion data have been used to study the circulation regimes and winter-to-winter variability of Arctic sea-ice motion. The relation between sea-ice motion and the pressure field in the Arctic Ocean was also studied by applying Principal Component Analysis (PCA) to the monthly merged sea-ice motion data and the monthly pressure field data from IABP. The mean Arctic sea-ice motion map of the 15 winter seasons has two distinct features: the Beaufort Gyre and a cyclonic circulation system in the Eurasian Basin, which moves ice from the Laptev Sea to Fram Strait. The strengths and sizes of the two features change from one winter season to another. Seasons with a strong or normal Beaufort Gyre alternate with seasons with a weak or no Beaufort Gyre every one to three seasons. The principal components of the first two modes of PCA of the monthly sea-ice motion are closely correlated with their counterparts of the monthly pressure field in the Arctic Ocean. The mode-one components of these two anomalies alternate between anticyclonic and cyclonic circulation systems. The correlation between Arctic Oscillation indexes and the principal components of the first mode of PCA of the monthly Arctic sea-ice motion is low but statistically significant.     

综合应用测井及地震资料建立复杂断块地质模型

针对滩海油田具有完钻井少,以地震资料为主的特点,采用井震结合的方法进行地质建模。复杂断块油藏具有许多内部断层,充分利用地震解释层位和断层成果建立合理的构造模型。采用“多步建模”的思路,选用序贯高斯同位协同模拟算法建立储层参数模型。以测井资料为硬数据,地震反演数据为软数据,先后建立自然伽玛模型、泥质含量模型和砂泥岩相模型,然后以砂泥岩相模型为约束,建立储层参数模型。经研究表明,综合使用地震解释成果和三维地震数据体,有助于建立准确、合理的构造模型;而采用“多步建模”的思路,利用序贯高斯同位协同模拟算法,并综合测井资料、地震资料建立储层参数模型,有助于从地质的角度对储层参数模拟进行约束,提高储层随机建模精度,保证储层参数模型的准确和可靠性。     

MODIS数据北京城区热岛监测分析

随着城市化进程的深入,热岛效应问题越来越严重,从而影响城市及周边地区的生态环境与气候,因此备受人们的重视。本文从2000年—2007年724幅1km分辨率的MODIS地表温度产品中选取64幅质量较好,可以代表春、夏、秋、冬四个季节的昼夜影像,制作地表温度图和选取感兴趣区域分析北京城区热岛效应。结果表明,北京市城区温度明显高于周围地区,夏季夜间最高达到3.7℃,秋季白天相对热岛强度较大,夏季、冬季夜间热岛强度要大于白天,尤其冬季较为明显。     

Contributions of Fuqing ZHANG to Predictability,Data Assimilation,and Dynamics of High Impact Weather: A Tribute

This article reviews Fuqing ZHANG’s contributions to mesoscale atmospheric science,from research to mentoring to academic service,over his 20-year career.His fundamental scientific contributions on predictability,data assimilation,and dynamics of high impact weather,especially gravity waves and tropical cyclones,are highlighted.His extremely generous efforts to efficiently transmit to the community new scientific knowledge and ideas through mentoring,interacting,workshop organizing,and reviewing are summarized.Special appreciation is given to his tremendous contributions to the development of mesoscale meteorology in China and the education of Chinese graduate students and young scientists.     

常用GPS载波相位差分电文格式分析与比较

介绍了差分GPS传输载波相位差分信息的常用电文格式，比较了其优缺点，提出了在低带宽的条件下更适合采用CMR格式的结论。     

一种基于事件的双序列时空数据模型

针对现有时空数据模型研究中存在的诸多不足,特别是基于事件的时空模型缺乏以空间对象个体为单位的时空变化贯穿式表达能力等缺点,提出一种基于事件的双序列时空数据模型,将状态变化与空间对象的变化用双重序列表达,用序列存储对象的变化解决了现有时空数据模型基于空间对象个体时空变化信息表达能力弱的问题。实验表明,该模型可有效用于时空数据管理。