起算点精度对GPS基线解算质量的影响

基线处理时要求知道一个点的坐标,其精度对GPS基线的解算结果有影响。采用实测数据研究起算点精度对GPS基线解算质量的影响,得出了其影响规律,同时给出了提高起算点精度的方法。     

利用有理函数模型实现IKONOS影像的单片定位

分析了利用高分辨率卫星CCD影像进行单片测图的意义，介绍了目前有理函数模型在影像定位方面的应用情况，重点研究了一种利用有理函数模型实现单片定位的方法，即将有理函数模型的正解形式线性化并组成方程组，结合DEM数据，对方程组迭代求解以获取地面点坐标。实验结果表明该方法具有解算精度高和易实现等特点。     

SPOT遥感影像处理技术以及在青岛市海洋功能区划中的应用

青岛市海洋功能区划中，大范围采用了法国高分辨率陆地卫星SPOT-5HRG 1A级遥感数据。利用Geoimage遥感影像处理软件对数据进行了处理．包括：遥感影像的正射纠正、辐射处理和不同分辨率影像地融合等，获得了高空间分辨率和良好的光谱分辨率的遥感图像。很好的识别出青岛海岸带地区地物分布特征。为海洋功能区划底图补充了真实而丰富的信息．     

一种建立局域无缝海图深度基准面的方法

根据海洋测绘中垂直基准构建的需求,提出了一种基于主成分-逐步回归分析的建立局域无缝海图深度基准面的方法。在此基础上,利用中国某海区多个验潮站深度基准面值及分潮调和常数振幅,建立了该海区局域无缝深度基准面值回归方程。实例计算表明,该方法所建立的局域海区无缝海图深度基准面值能够达到厘米级精度,可为海图深度基准面体系的重新构建提供技术支持。     

Research and Test of Real-time Search Algorithm of Fast Radio Bursts Based on GPU Acceleration

In order to satisfy the research need of Nanshan 25 m radio telescope of Xinjiang Astronomical Observatory (XAO) and study the key technology of the planned QiTai radio Telescope (QTT), on the basis of the original CPU (Central Processing Unit)-based real-time search algorithm of FRBs (Fast Radio Bursts), we have studied the GPU (Graphics Processing Unit)-based real-time search algorithm of FRBs, and built the corresponding real-time search system of FRBs. We have made the comparison and analysis on the GPU system and CPU system, the test result shows that under a given searching accuracy, the speed of the GPU-accelerated algorithm is improved by 35–45 times compared with that of the CPU algorithm.     

Research on the Application of Fast-steering Mirror in Stellar Interferometers

In stellar interferometers, the fast-steering mirror (FSM) is widely utilized to correct the wavefront tilt caused by the atmospheric turbulence and internal instrumental vibration, because of its high resolution and fast response frequency. In this study, the non-coplanar error between the FSM and the actuator deflection axis introduced by the manufacturing, assembly, and adjustment is analyzed systematically. Via a numerical method, the additional optical path difference (OPD) caused by the above factors is studied, and its effect on the fringe tracking accuracy of a stellar interferometer is also discussed. On the other hand, the starlight parallelism between the beams of two arms is one of the main factors for the loss of fringe visibility. By analyzing the influence of wavefront tilt caused by the atmospheric turbulence on fringe visibility, a simple and efficient real-time correction scheme of starlight parallelism is proposed based on a single array detector. The feasibility of this scheme is demonstrated by a laboratory experiment. The results show that after the correction of fast-steering mirror, the starlight parallelism meets preliminarily the requirement of a stellar interferometer on the wavefront tilt.     

Using advanced soft computing techniques for regional shoreline geoid model estimation and evaluation

This study aims at evaluating the global geoid model for a regional shoreline fitting using advanced soft computing techniques and global navigation satellite system/leveling measurements. Artificial neural networks, fuzzy logic, and least square support vector machine models are developed and used to fit the global geoid model for the north coastal Egyptian line. In addition, a novel estimation geoid model is designed and evaluated based on the latest global geoid models. The results of the three estimation models show that they can be used to correct the shoreline geoid model, in terms of root mean square error that ranges from 1.7 to 8.5?cm. Moreover, it is found that the least square vector machine model is a competitive approach with certain advantage in solving complex problems represented by missing data.     

粘性土微结构形态要素及其定量信息处理技术

本文论述了粘性土微结构的形态要素及其层次关系，提出了11种结构参数并难予了相应的图像定义；以分形理论为基础确定了7项非线性结构要素的定量描述方法及其分维指标，并对其定量信息获取手段——粘性土微结构图象处理系统（MIPS）作了简要介绍。     

湖南省似大地水准面2017模型及精度分析

利用近7万个湖南及邻近省份重力观测数据、502个GNSS/水准控制点及数字高程模型,以EIGEN-6C4全球重力场模型作参考重力场,采用顾及地球曲率影响的各类地形质量位及引力的第二类Helmert凝集法严密算法,利用高分辨率地形数据恢复甚短波扰动重力场,确定空间分辨率2′×2′的高精度湖南省似大地水准面模型（HNGG2017）。经外部检核,模型整体精度均优于±0.022 m。与历史模型相比,新模型在湖南北部常德汉寿、西南部永州江永等地区精度得到显著改善。     

GPS天线相位中心校正对GRACE卫星精密定轨的影响

使用GRACE卫星星载GPS观测数据,研究地面获取的先验PCV模型和利用残差法估计的在轨PCV模型对低轨卫星精密定轨的影响,并采用GFZ精密轨道对比和SLR检核手段对其进行评估。结果表明,使用先验PCV模型会降低GRACE卫星定轨精度,相反利用在轨PCV模型可以提高定轨精度,提升数量级可达mm级。