GPS动态定位中机动随机模型分析

给出了载体状态方程的严密公式和常用近似公式,详细讨论了两者之间的区别。在高精度ＧＰＳ动态定位中的应用证明,常用近似公式对载体速度和加速度有显著的影响。     

迭代扩展卡尔曼滤波用于实时GPS数据处理

标准的卡尔曼滤波可以扩展到非线性模型,即将泰勒公式应用于状态方程和观测方程,得到扩展卡尔曼滤波公式。首先推导了计算公式,研究了迭代计算方法,并将其用于ＧＰＳ数据的实时处理。     

GPS高程拟合的几种常用方法

对GPS高程拟合的几种常用方法进行了较为细致的讨论,给出了具体的数学模型,结合实测数据对各种拟合方法的特性进行了分析比较。     

GPS网与地面网的坐标连接

本文对坐标系统的转换以及坐标的拟合推估进行了论述。     

External atmospheric corrections in geodetic very-long-baseline interferometry

Three methods to correct for the atmospheric propagation delay in very-long-baseline interferometry (VLBI) measurements were investigated. In the analysis, the NASA R&D experiments from January 1993 to June 1995 were used. The methods were compared in correcting for the excess propagation delay due to water vapour, the “wet” delay, at one of the sites, the Onsala Space Observatory on the west coast of Sweden. The three methods were: (1) estimating the wet delay using the VLBI data themselves; (2) inferring the wet delay from water vapour radiometer (WVR) data, and (3) using independent estimates based on data from the global positioning system (GPS). Optimum elevation cutoff angles were 22^∘ and 26^∘ when using WVR and GPS data, respectively. The results were found to be similar in terms of reproducibility of the estimated baseline lengths. The shortest baselines tend to benefit from external measurements, whereas the lack of improvement in the longer baselines may be partly due to the large amount of data thrown away when removing observations at low elevation angles. Over a 2 week period of intensive measurements, the two methods using external data showed an overall improvement, for all baseline lengths, compared to the first method. This indicates that there are long-term systematic errors in the wet delay data estimated using WVR and GPS data. Received: 27 October 1998 / Accepted: 20 May 1999     

GPS网与常规网三维联合平差的一种简便模型

提出了GPS控制网与常规控制网三维联合平差时分别固定平面坐标与高程的简便方法,从而简化了三维联合平差的模型,并给出算例验证了模型。     

Preliminary Study on Horizontal Deformation and Tectonic Activity in the Northern Part of North China Using GPS Remeasurement Results

In this paper, the baseline variation and displacement vector was analyzed using the calculated results of GPS measurements carried out from 1995 to 1996 in North China. Based on these analytical results, we studied the recent tectonic activity. In general, the regional extension is dominant in the direction of proximately EW, but there is a difference in the SN direction. Extension is significant in the Shanxi fault-depression zone and Bohai region, while compression with strike-slip is characterized along the Yishui-Tancheng segment of the Tanlu fault zone. The baseline shortening zone is distributed along the Baotou-Zhangjiakou-Ninghe areas. It is a boundary zone of regional variation where many differences of crustal horizontal deformation are discovered between the southern part and the northern part of this zone. The baseline shortening zone in NE direction is distributed along the Jianchang-Tangshan-Gucheng area. It is consistent with the Tangshan-Xingtai seismic zone which indicates that tectoni     

GPS工程控制网投影变形的处理

在ＧＰＳ工程控制网建立的内业处理中,为后续的方便必须设法高斯投影变形对坐标成果的影响,本文在简要介绍了常规投影变形处理方法之后,提出了尺度强制约束和投影面重新选择两种投影变形的处理方法。工程实践检验表明,两种方法不但可行而且可使处理后的坐标系统与国家坐标系统尽可能保持一致,方便了工程使用。     

GPS中CCD技术的原理与应用

码／载波相位扩散技术可使单频ＧＰＳ接收机的测程从２０ｋｍ急剧扩大到４００ｋｍ。本文叙述其简单原理与实际应用。     

机载三维成像仪的定位原理与误差分析

本文论述了“机载三维成像仪”的定位原理,并在系统定位原理的基础上,详细讨论了与“机载三维成像仪”的对地定位精度有关的传感器的误差对系统定位精度的影响,这一问题的研究不仅对研制针对不同目的的激光地形制图系统的设计具有指导意义,而且对激光扫描制图系统的数据平差具有重要意义。