近地小行星轨道演化的研究

本文主要阐述了近年来我们在近地小行星轨道演化研究所获得的一些基本结果,即合理的力学模型和相应的有效算法,并以实际预报算例与有关权威性的结果作了比较,证实这些研究结果确实是可信的。     

Secular changes of LOD associated with a growth of the inner core

From recent estimates of the age of the inner core based on the theory of thermal evolution of the core, we estimate that nowadays the growth of the inner core may perhaps contribute to the observed overall secular increase of LOD caused mainly by tidal friction (i.e., 1.72 ms per century) by a relative decrease of 2 to 7 µs per century. Another, albeit much less plausible, hypothesis is that crystallization of the inner core does not produce any change of LOD, but makes the inner core rotate differentially with respect to the outer core and mantle. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

论新世纪衡阳城市形象的定位与塑造

衡阳市以位处南岳衡山之南而得名,自古以来自然、人文景观并胜,社会、经济、文化发达.近20多年来各方面反而停滞和落后.文中运用企业识别CI原理,从城市形象发展历史和现状入手,将其新世纪城市总体形象定位为"江南内陆腹地重要现代化区城中心 ,湘南最大交通枢纽,全国著名的山水旅游城市,环境优美、安全舒适的人居休闲胜地". 并指出城市形象塑造应体现古城衡阳的气韵和文脉,给人以古老文明、开拓进取、不断创新的总体视觉形象,以推动新世纪衡阳城市的总体发展.     

合成孔径雷达( SAR)及其在地质和地震研究中的应用

在遥感技术广泛应用的今天, 合成孔径雷达( SAR)因其具有全天时、全天候成像能力及对地物有一定穿透力等独特的特点, 已成为地学研究的一个重要手段。概述了合成孔径雷达技术的发展状况, 对合成孔径雷达成像机理及特征做了简要介绍, 同时对新兴起的合成孔径雷达干涉测量( IN SAR)技术也做了简单描述, 并就SAR在地质和地震研究中的应用进行了举例说明, 充分肯定了合成孔径雷达技术在地质和地震研究中的重要作用。     

Two‐body system with a rotating central body (e.g. Earth‐Moon system) within the Projective Unified Field Theory

In this treatise the well‐known 2‐body problem with a rotating central body is systematically reinvestigated on the basis of the Projective Unified Field Theory (PUFT) under the following aspects (including the special case of the Newton mechanics): First, equation of motion with abstract additional terms being appropriate for the interpretation of the various effects under discussion: tidal friction effect as well as non‐tidal effects (e.g. rebound effect as temporal variation of the moment of inertia of the rotating body, general‐relativistic Lense‐Thirring effect, new scalaric effects of cosmological origin, being an outcome of the scalarity phenomenon of matter (PUFT). Second, numerical evaluation of the theory. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Climate Comparisons and Change Projections for the Northwest Atlantic from Six CMIP5 Models

Abstract

Key physical variables for the Northwest Atlantic (NWA) are examined in the “historical” and two future Representative Concentration Pathway (RCP) simulations of six Earth System Models (ESMs) available through Phase 5 of the Climate Model Intercomparison Project (CMIP5). The variables are air temperature, sea-ice concentration, surface and subsurface ocean temperature and salinity, and ocean mixed-layer depth. Comparison of the historical simulations with observations indicates that the models provide a good qualitative and approximate quantitative representation of many of the large-scale climatological features in the NWA (e.g., annual cycles and spatial patterns). However, the models represent the detailed structure of some important NWA ocean and ice features poorly, such that caution is needed in the use of their projected future changes. Monthly “climate change” fields between the bidecades 1986–2005 and 2046–2065 are described, using ensemble statistics of the changes across the six ESMs. The results point to warmer air temperatures everywhere, warmer surface ocean temperatures in most areas, reduced sea-ice extent and, in most areas, reduced surface salinities and mixed-layer depths. However, the magnitudes of the inter-model differences in the projected changes are comparable to those of the ensemble-mean changes in many cases, such that robust quantitative projections are generally not possible for the NWA.     

First results of the earth observation Water Cycle Multi-mission Observation Strategy (WACMOS)

Observing and monitoring the different components of the global water cycle and their dynamics are essential steps to understand the climate of the Earth, forecast the weather, predict natural disasters like floods and droughts, and improve water resources management. Earth observation technology is a unique tool to provide a global understanding of many of the essential variables governing the water cycle and monitor their evolution from global to basin scales. In the coming years, an increasing number of Earth observation missions will provide an unprecedented capacity to quantify several of these variables on a routine basis. However, this growing observational capacity is also increasing the need for dedicated research efforts aimed at exploring the potential offered by the synergies among different and complementary EO data records. In this context, the European Space Agency (ESA) launched the Water Cycle Multi-mission Observation Strategy (WACMOS) in 2009 aiming at enhancing, developing and validating a novel set of multi-mission based methods and algorithms to retrieve a number of key variables relevant to the water cycle. In particular the project addressed four major scientific challenges associated to a number of key variables governing the water cycle: evapotranspiration, soil moisture, cloud properties related to surface solar irradiance and precipitation, and water vapour. This paper provides an overview of the scientific results and findings with the ultimate goal of demonstrating the potential of strategies based on utilizing multi-mission observations in maximizing the synergistic use of the different types of information provided by the currently available observation systems and establish the basis for further work.     

基于影像交叉学习的CBERS CCD波段模拟

与TM/ETM+相比,CBERS CCD缺少2个红外波段(波段5和波段7),这便导致了许多针对TM/ETM+数据的图像处理方法难以直接应用于CBERS CCD图像.为此,采用基于影像交叉学习的波段模拟方法,即以ETM+数据作为先验知识,通过支持向量回归( Support Vector Regression,SVR),拟...     

基于osgEarth的虚拟校园场景建模研究

osgEarth是一个基于OSG开发的实时地形模型加载和渲染工具。本文对数字地球及其应用进行了介绍,同时探讨了建设虚拟校园场景的关键技术。接着使用osgEarth获取了Google Earth的数据并且建立了数字地球底图,然后使用本地地形数据和3维模型建立了西南交通大学虚拟场景。最后发布了虚拟校园场景,从而使用户能够通过网络浏览该场景。     

机载POS系统中惯性测量单元精度检校方法

本文简要介绍了GPS/INS组合技术的优势和特点,分析了惯性测量单元(IMU)的工作原理及精度影响因素,系统阐述了机载POS系统中IMU的检校方法和精度评定方法,包括初始对准重复性检测、跟踪姿态角精度的标定和静态漂移检测等,并利用双轴数控转台,对3台不同类型的国产POS系统进行了数据采集、处理和对比分析,实验初步表明,...