区间值直观模糊集的直积与相关性

在区间值直观模糊集上定义新的算子,给出这些关系与算子之间的一些重要性质,并讨论了区间值直观模糊集的相关性问题.     

Resourcesat-1 mission planning,analysis and operations—Outline of key components

Resourcesat-1 is a global mission which provides continuity to the earth resources monitoring missions earlier launched by India. Resourcesat-1 is designed to have an improvement in the payload camera characteristics providing multi-spectral imaging capability in high resolution. This paper provides an overview of mission planning and analysis aiding spacecraft configuration, pre-launch simulations and operations, early-orbit operations and the on-orbit operational guidelines for Resourcesat-1. Mission planning involved integrating and inter-relating the efforts of space and ground systems in realizing the operational system which provides the continuity of satellite-based remote sensing data to the user community. Mission analysis related to contiguous imaging requirement of LISS-4 payload, resulted in a spacecraft yaw steering during imaging operations. Pre-launch simulation involved development of a software spacecraft simulator to be used as a tool for network tests, training of spacecraft operation personnel and validating the spacecraft health monitoring software. The required operations that were performed on the spacecraft to characterize and establish the on-orbit configuration for the normalization of daily operations are addressed in the sections relating to early orbit operations and on-orbit operational guidelines.     

The dynamical environment of Dawn at Vesta

Dawn is the first NASA mission to operate in the vicinity of the two most massive asteroids in the main belt, Ceres and Vesta. This double-rendezvous mission is enabled by the use of low-thrust solar electric propulsion. Dawn will arrive at Vesta in 2011 and will operate in its vicinity for approximately one year. Vesta's mass and non-spherical shape, coupled with its rotational period, presents very interesting challenges to a spacecraft that depends principally upon low-thrust propulsion for trajectory-changing maneuvers. The details of Vesta's high-order gravitational terms will not be determined until after Dawn's arrival at Vesta, but it is clear that their effect on Dawn operations creates the most complex operational environment for a NASA mission to date. Gravitational perturbations give rise to oscillations in Dawn's orbital radius, and it is found that trapping of the spacecraft is possible near the 1:1 resonance between Dawn's orbital period and Vesta's rotational period, located approximately between 520 and 580 km orbital radius. This resonant trapping can be escaped by thrusting at the appropriate orbital phase. Having passed through the 1:1 resonance, gravitational perturbations ultimately limit the minimum radius for low-altitude operations to about 400 km, in order to safely prevent surface impact. The lowest practical orbit is desirable in order to maximize signal-to-noise and spatial resolution of the Gamma-Ray and Neutron Detector and to provide the highest spatial resolution observations by Dawn's Framing Camera and Visible InfraRed mapping spectrometer. Dawn dynamical behavior is modeled in the context of a wide range of Vesta gravity models. Many of these models are distinguishable during Dawn's High Altitude Mapping Orbit and the remainder are resolved during Dawn's Low Altitude Mapping Orbit, providing insight into Vesta's interior structure. Ultimately, the dynamics of Dawn at Vesta identifies issues to be explored in the planning of future EP missions operating in close proximity to larger asteroids.     

现有业务系统建设GIS的模式分析与实践

随着信息化的发展,建设GIS的门槛已经逐步降低,GIS技术也越来越普及,如何在现有业务系统的基础上建设GIS已经成为普遍面临的一个问题。总结了3种建设模式,并对它们的主要区别和优缺点进行了比较分析,最后结合一个项目实践阐述了附加包装模式的具体实现过程。     

Sensor Calibration in Support for NOAA’s Satellite Mission

Sensor calibration, including its definition, purpose, traceability options, methodology, complexity, and importance, is examined in this paper in the context of supporting NOAA’s satellite mission. Common understanding of sensor calibration is essential for the effective communication among sensor vendors, calibration scientists, satellite operators, program managers, and remote sensing data users, who must cooperate to ensure that a nation’s strategic investment in a sophisticated operational environmental satellite system serves the nation’s interest and enhances the human lives around the world. Examples of calibration activities at NOAA/NESDIS/ORA are selected to further illustrate these concepts and to demonstrate the lessons learned from the past experience.     

Chemical analysis of contaminated soil strengthened by the addition of lime

Strengthening of contaminated materials using inorganic cementitious agents is becoming more widely used in the UK. The method has particular advantages for bulk fill operations such as highway earthworks. Research has been done into the chemical characteristics of leachates and leached solid samples from a study into the long-term durability of a lime strengthened silt/pfa mixture amended with sewage sludge. This involved determinations of chemical composition and mineralogy, and geochemical modelling using . None of the heavy metals tested is present in the leachate at a concentration likely to pose a significant environmental threat, although some were present to a higher degree than expected based on the inorganic chemistry. This is ascribed to complexation of the heavy metals with dissolved organic matter.     

数字地图制图中多源数据(资料)的综合应用

探讨了数字地图制图中多源数据综合应用的技术方法,主要内容包括多源数据(资料)的分类、分析与评价;数据获取和基本的处理方法.最后介绍了利用TM影像、全国公路网GPS测量数据和数字海图等几种数据源制作1:25万协同图的相关情况.     

库岸滑坡地质灾害三维演变动态显示方法

以澜沧江糯扎渡水电站某大型滑坡为例,在数值分析计算的基础上,运用集大规模数据运算和可视化为一体的IDL语言研究并实现了三维场景中滑坡滑落、滑坡入水激起涌浪以及涌浪传播3个过程的动态集成显示方法。首先,对数据更新部分进行数据提取以及分离运算,以此降低数据更新的难度;其次,将三维滑坡场景细分成地形、滑坡体和河道水面3个对象,以提高每一个部分的可控制性;最后,将滑坡滑落过程、滑坡入水激起涌浪过程以及涌浪的传播过程集成为一个动态整体,再现了滑坡地质灾害演变过程。结果表明,整个滑坡动态演变过程之间衔接平稳,各对象数据操作简便,对象的可控制性高,整体稳定性好。     

新疆阿克苏地区冰雹时空分布及雷达回波特征

利用"新疆气象灾情直报系统"冰雹灾情数据和阿克苏地区人工防雹作业信息,分析了阿克苏地区9县市2010—2019年冰雹天气的时间变化和空间分布特征,选用阿克苏地区9县市2009—2019年10场冰雹天气过程,应用美国Gibson Ridge Software LLC公司GR2Analyst雷达产品处理软件分析二次产品,得...     

基于知识的GIS专题数据综合的研究

分析了GIS专题数据综合知识的分类体系,采用人工智能技术的产生式规则表示法将综合知识形式化为综合规则,并分析了GIS专题数据综合规则体系的形成模式;用实例分析比较了运用规则和不运用规则产生的不同综合结果,并以此进一步体现围绕特定应用专题的专题知识对专题数据综合的重要性。