关于我国天测与测地VLBI网络未来建设的讨论

结合国内外VLBI技术发展的历史、现状与动态,从天体测量、空间大地测量和深空探测等角度,对我国天测与测地VLBI观测网络的未来建设进行了需求分析和测站配置技术指标分析。     

The Digital Belt and Road program in support of regional sustainability

The Belt and Road initiative has a significant focus on infrastructure, trade, and economic development across a vast region, and it also provides significant opportunities for sustainable development. The combined pressure of climate variability, intensified use of resources, and the fragility of ecosystems make it very challenging, however, to achieve future sustainability. To develop the path in a sustainable way, it is important to have a comprehensive understanding of these issues across nations and evaluate them in a scientific and well-informed approach. In this context, the Digital Belt and Road (DBAR) program was initiated as an international venture to share expertise, knowledge, technologies, and data to demonstrate the role of Earth observation science and technology and big Earth data applications to support large-scale development. In this paper, we identify pressing challenges, present the research priorities and foci of the DBAR program, and propose solutions where big Earth data can make significant contributions. This paper calls for further joint actions and collaboration to build a digital silk road in support of sustainable development at national, regional and global levels.     

Integrating ASTER and GLASS broadband emissivity products using a multi-resolution Kalman filter

In this study, the multi-resolution Kalman filter (MKF) algorithm, which can handle multi-resolution problems with high computational efficiency, was used to blend two emissivity products: the Global LAnd Surface Satellite (GLASS) (BBE) product and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) narrowband emissivity (NBE) product. The ASTER NBE product was first converted into a BBE product. A new detrending method was used to transfer the BBEs into a process suitable for the MKF. The new detrending method was superior to the two existing methods. Finally, both the de-trended GLASS and ASTER BBE products were incorporated into the MKF framework to obtain the optimal estimation at each scale. Field measurements collected in North America were used to validate the integrated BBEs. Visually, the fusion map showed good continuity, with the exception of the border areas, and the quality of the fusion map was better than that of the original maps. The validation results indicate that the MKF improved the BBE product accuracy at the coarse scale. In addition, the MKF was capable of recovering missing pixels at a finer scale.     

局部均值分解与支持向量回归的大坝变形预测

针对现有变形预测方法对于大坝变形的预测效果不理想的问题,该文利用局部均值分解方法获取生产函数分量并进行支持向量回归建模,用此方法对大坝变形进行多尺度分析。通过局部均值分解对大坝变形序列进行分解得到其乘积函数分量,然后利用支持向量机回归进行外推预测,再把各乘积函数分量的预测结果进行叠加重构生成,进而获得大坝变形预测值。通过实例分析,比较GM(1,1)、支持向量机和该文方法3种模型在变形监测数据处理中的拟合和预测结果,表明该文方法充分发掘数据本身所蕴含的物理机制和物理规律,提高了大坝变形多尺度预测精度。     

恶劣环境下GPS/BDS混合双差模糊度固定性能分析

针对在恶劣观测环境下每个GNSS系统只观测到较少的几颗卫星,采用标准双差模型很难实现整周模糊度固定的问题,该文对GPS/BDS系统间混合双差模型进行研究,利用该模型计算出GPS/BDS系统偏差。在此基础上,利用实验分别对模拟和真实恶劣观测环境下的模糊度固定性能进行分析,实验结果表明,恶劣环境下GPS/BDS系统间混合双差模型表现良好,相较于经典的双差模型可将模糊度固定平均所需时间分别缩短43%和33%,模糊度固定成功率分别提高107%和31%。     

附有限制条件的间接平差与附有条件的条件平差的内在联系探讨

通过运用附有条件的条件平差原理解算附有限制条件的间接平差模型,以及运用附有限制条件的间接平差原理解算附有条件的条件平差模型,推证得出结论:对于同一个平差问题而言,这两种平差模型是完全等价的,都可作为各种经典平差模型的概括平差模型。     

中国-日本绝对重力仪器测量比对结果

本文给出了中科院测地所FG5-112和日本京都大学FG5-201及日本国土地理院FG5-104等几台绝对重力仪在武汉九峰和香港天文台绝对重力测量比对结果。分析说明不同仪器间具有良好的一致性,其中FG5-112与FG5-104结果间的互差达8×10-8m/s2;FG5-112与FG5-201和FG5-104等的观测互差小于2×10-8m/s2。这种比对观测,可为深入了解仪器性能和精确测定不同台站重力非潮汐变化提供可靠参考。     

古田溪一级大坝变形观测系统改造及自动化设计

本文介绍了古田汉一级大坝原有变形观测项目及存在的主要问题，提出了观测系统改造的原则和要求。详细论述了各观测项目增设、改造及自动化设计的实施方案，给出了相应的精度估算。     

基于空间网络分析的高速公路网一类调查观测站布设技术

在数量适度的情况下,合理布设高速公路交通量调查观测站点,使观测数据准确反映路网运行特征是高速公路交通量调查与信息服务体系构建的重要支撑。文中运用GIS空间网络分析技术,结合"两阶段"宏观布设法和OD反推布设法,开发交通量调查观测站布设软件。当缺少历史流量数据时,用"两阶段"宏观布设法以路段累计重要度代替路段流量,并进行累计重要度计算。最后以江苏省高速公路网一类调查观测站布设为例进行验证,结果表明,软件可基本实现科学、高效的高速公路一类调查观测站布设。     

论自动化和智能化空间对地观测数据处理系统的建立

未来１０年遥感对地观测技术的发展使得遥感影像的获取将走向多种传感器、多分辨率、多谱段和多时相。各国计划发射的对地观测卫星将使我们能够同时获取大量的、不同分辨率的、多谱段的可见光、红外、微波辐射和侧视雷达的数据。从而构成用于全球变化研究、环境监测、资源调查、灾害防治的多层次遥感影像金字塔。为了能够及时地、充分地利用这些对地观测数据来回答地学研究和人类社会发展所面临时的问题，更好地发挥遥感为国民经济建设服务的巨大潜力，必须从技术上建立一个自动化和智能化的空间对地观测数据处理系统。鉴于目前应用滞后于发射，软件落后于硬件的现实情况，本文简要叙述建立自动化和智能化空间对地观测数据处理系统的必要性和可能性，分析建立该系统的主要目标和需解决的关键技术并希望国家集中各有关方面的人力和财力来共同攻关，以建立和完善我国的地球科学信息系统，提高综合研究与深入分析的现代化水平。