卫星在轨颤动检测的可行性研究

卫星在轨颤动检测对CCD相机成像质量检测具有决定性,对图像应用潜力也是决定性的。利用快速小面阵CCD获取图像序列,提取任意时刻的参考图像与颤动图像进行SIFT初定位,利用RANSAC剔除SIFT位存在的粗差,结合图像运动模型,解算颤动状态参数。通过实验论证,此种方法检测在轨颤动是可行的、有效的。     

The Second Modified Perpendicular Drought Index (MPDI1): A Combined Drought Monitoring Method with Soil Moisture and Vegetation Index

Since soil moisture and vegetation index are direct and important indicators for surface drought status, a new drought monitoring method (MPDI1) is developed in NIR-Red reflectance space. It is a combination of two satellite-derived variables—a soil moisture component using the Perpendicular Drought Index (PDI), and a vegetation component using the Perpendicular Vegetation Index (PVI). Enhanced Thematic Mapper Plus (ETM+) image and in-situ ground observation are introduced to validate the accuracy of the proposed method. Results indicate that MPDI1 is highly consistent to the in-situ ground observation with the coefficient of determination (R²?=?0.49) between MPDI1 and 5–20 cm mean soil moisture, which is slightly higher than the coefficient of determination (R²?=?0.42) between MPDI1 and 10 cm soil moisture. Compared with drought indices such as PDI and the Modified Perpendicular Drought Index (MPDI), MPDI1 provides quite similar trends for bare soil or lower vegetated surface, but it demonstrates a better performance in measuring densely vegetated surface. This paper concludes that MPDI1 provides correct and sufficient information on surface drought status in soil-plant continuum, which appears to have robust available and great potential for surface drought estimation in China and other countries.     

彩色扫描地图中背景色的等高（等深）线矢量化研究

在介绍矢量化方式的基础上,根据国外地图的特点,选择了基于全要素地图的矢量化方式。通过综合利用多义点及方向信息,对等高线矢量化的追踪过程控制,不仅避免了误追踪等特殊情况,且减少了人机交互,实现了有背景色区域等高（等深）线的半自动矢量化。     

一类捷联惯导系统模糊内阻尼算法的改进

讨论了内阻尼网络对捷联惯导系统的影响,指出载体在导航系内的加速度直接影响系统精度;分析了相关文献模糊内阻尼算法的适用前提及局限性,并提出改进算法。首先利用载体解算的姿态和速度信息对载体系内加速度计输出信息进行相应坐标变换和补偿;而后采用固定点滤波对其进行消噪处理;最后将处理后的数据输入模糊判别器以判断捷联惯导系统的工作方式。仿真和试验结果显示,本文算法更能准确地判断载体运动状态。46h海上导航数据表明,本文算法能准确判断舰船状态而合理选择系统阻尼状态,使系统最大速度误差由2m/s提高到1m/s。     

边疆少数民族地区高校《遥感基础与应用》课程教学的几点思考和体会

《遥感基础与应用》课程是土地资源管理专业的专业必修课,根据边疆少数民族地区高校学生的特点,按照因材施教的原则对汉族和民族学生区别教学,确定不同的教学内容和教材。采用启发-互动式、鼓励加分式教学,充分利用多媒体丰富课堂内容,尝试创新性实验教学,激发学生的学习兴趣,提高教学质量。     

Towards a 1 mGal accuracy and 1 min resolution altimetry gravity field

Over the past three decades, radar altimetry has made a significant contribution to marine gravity field modeling. To improve the accuracy and resolution, we propose a new twin-satellite altimetry. Such a system has several advantages. Among others, it provides (i) twice the number of samples per time epoch, and (ii) information about the cross-track surface gradient with high accuracy because most of the environmental and tidal errors will be common to the simultaneous measurements and therefore cancel out when computing the cross-track gradient computation. We describe a rigorous procedure for the deduction of the sea surface gradient at each altimeter observation point (i.e., not only at the crossovers), from the twin-satellite altimetry system. The precision of the gradient will be slightly affected by orbit errors, instrument drift, and inaccuracies in the geophysical corrections to be applied. We also demonstrate that a 1 mGal accuracy and 1 min resolution marine altimetry gravity field can be obtained if certain conditions are met. To achieve the expected goal, we recommend an orbital configuration, phasing two satellites in 4-s time delay such that the Earth rotation creates a natural baseline between the two satellites, and a 18 kHz SAR altimeter.     

卫星定位与导航教学的改革与实践

通过研究分析CDIO理念和卓越工程师计划,本文将CDIO理念和卓越工程师培养计划引入到卫星定位与导航的课程教学中,对教学过程中的教学内容、教学方法、实践教学模式和考核方法进行了改革,取得了良好的效果,同时对其他课程的教学具有一定的指导和借鉴意义。     

以宗地统一代码为核心加快推进国家电子文件管理系统建设

尊敬的王世元副部长,各位领导、同志们： 上午好!很高兴应邀参加国土资源部在吉林长春召开的试点工作会议。首先我代表国家电子文件管理部际联席会议办公室对“全国宗地统一代码电子文件管理试点工程”项目启动会议的召开表示祝贺!下面,我把国家电子文件管理试点工作的情况和一些想法与大家交流—下。     

关于国土资源信息化标准工作的几点建议

本文结合国土资源信息化标准工作现状,对标准制定、修订工作提出建议,阐述了地方标准的重要作用,提出了开展地方标准指导、监督和试点示范工作的办法,以及通过加强监督、及时发布和培训、建立标准管理服务平台加强标准宣贯工作的建议。     

地理国情监测中地貌形态识别研究——以汶川地震核心灾区为例

监测地理国情,是经济社会发展到一定阶段的必然要求,地貌形态数据是重要的基础地理信息,地理国情监测中地貌形态识别是一项必要的基础工作。本文根据25m分辨率的DEM数据,以绝对高程和地形起伏度为地貌形态识别指标,建立适合汶川地震核心灾区的分类分级指标体系,采用数据分割的方法获得研究区6种地貌形态的分布图,识别结果真实可靠,对后续工作具有一定借鉴和指导意义。