"嫦娥"卫星绕月飞行轨道的激光测定法     

刘基余 《武汉大学学报(信息科学版)》2005,30(10):870-872,880

依据地月激光测距的成功实践和对卫星激光定轨的基础研究,提出了用地面对嫦娥卫星作激光测距的方法,高精度地测定嫦娥卫星绕月飞行时的实时在轨位置,论述了多站激光定轨和单站激光定轨的解算数模。  相似文献   

GPS新近发展及其军事应用   总被引：1，自引：0，他引：1  

刘晓萍  王晓迪 《测绘科学与工程》2005,25(3):51-54

本文简述了GPS的最新发展动态，着重分析了GPS在精确制导武器上的应用形式和效果，指出了GPS制导技术存在的局限性及其未来发展趋势。  相似文献   

Outlier detection algorithms and their performance in GOCE gravity field processing   总被引：2，自引：0，他引：2  

M. Kern  T. Preimesberger  M. Allesch  R. Pail  J. Bouman  R. Koop 《Journal of Geodesy》2005,78(9):509-519

The satellite missions CHAMP, GRACE, and GOCE mark the beginning of a new era in gravity field determination and modeling. They provide unique models of the global stationary gravity field and its variation in time. Due to inevitable measurement errors, sophisticated pre-processing steps have to be applied before further use of the satellite measurements. In the framework of the GOCE mission, this includes outlier detection, absolute calibration and validation of the SGG (satellite gravity gradiometry) measurements, and removal of temporal effects. In general, outliers are defined as observations that appear to be inconsistent with the remainder of the data set. One goal is to evaluate the effect of additive, innovative and bulk outliers on the estimates of the spherical harmonic coefficients. It can be shown that even a small number of undetected outliers (<0.2 of all data points) can have an adverse effect on the coefficient estimates. Consequently, concepts for the identification and removal of outliers have to be developed. Novel outlier detection algorithms are derived and statistical methods are presented that may be used for this purpose. The methods aim at high outlier identification rates as well as small failure rates. A combined algorithm, based on wavelets and a statistical method, shows best performance with an identification rate of about 99%. To further reduce the influence of undetected outliers, an outlier detection algorithm is implemented inside the gravity field solver (the Quick-Look Gravity Field Analysis tool was used). This results in spherical harmonic coefficient estimates that are of similar quality to those obtained without outliers in the input data.  相似文献   

Quality Assessment Of Digital Surface Models Generated From IKONOS Imagery     

Joanne  Poon  Clive S.  Fraser  Zhang  Chunsun  Zhang  Li  Armin  Gruen 《The Photogrammetric Record》2005,20(110):162-171

The growing applications of digital surface models (DSMs) for object detection, segmentation and representation of terrestrial landscapes have provided impetus for further automation of 3D spatial information extraction processes. While new technologies such as lidar are available for almost instant DSM generation, the use of stereoscopic high-resolution satellite imagery (HRSI), coupled with image matching, affords cost-effective measurement of surface topography over large coverage areas. This investigation explores the potential of IKONOS Geo stereo imagery for producing DSMs using an alternative sensor orientation model, namely bias-corrected rational polynomial coefficients (RPCs), and a hybrid image-matching algorithm. To serve both as a reference surface and a basis for comparison, a lidar DSM was employed in the Hobart testfield, a region of differing terrain types and slope. In order to take topographic variation within the modelled surface into account, the lidar strip was divided into separate sub-areas representing differing land cover types. It is shown that over topographically diverse areas, heighting accuracy to better than 3 pixels can be readily achieved. Results improve markedly in feature-rich open and relatively flat terrain, with sub-pixel accuracy being achieved at check points surveyed using the global positioning system (GPS). This assessment demonstrates that the outlook for DSM generation from HRSI is very promising.  相似文献   

佳木斯地区冬、春季大-暴雪成因分析     

闫世岩  陈东风 《黑龙江气象》2005,(2):2-3

冬、春季的天气影响系统既有共同点，又有不同之处。通过近20a大-暴雪个例的物理成因及卫星云图等特征的分析，总结出有预报意义的指标。  相似文献   

2001年影响广西的台风卫星云图特征分析     

黎声镭  陈翠敏 《气象研究与应用》2002,23(3):17-20

应用定性和定量分析方法 ,对 2 0 0 1年 4个影响广西的台风云图特征进行分析 ,发现旋转结构明显、组织结构紧密、面积大的台风云系 ,所产生的台风强度强、持续时间长、降水范围宽、过程雨量大  相似文献   

南疆西部山区一次特大暴雨特征分析     

胡翠珍 《沙漠与绿洲气象(新疆气象)》2002,25(3):9-11

通过对2001年9月22－23日南疆西北部山区特大暴雨的环流背景、物理量场、卫星云图分析，揭示了这场特大暴雨的物理机制和各要素场特征。  相似文献   

灌溉实时调度研究进展   总被引：16，自引：1，他引：16       下载免费PDF全文

顾世祥  傅骅  李靖 《水科学进展》2003,14(5):660-666

灌溉实时调度是农业水管理走向智能化、自动化和现代化的重要标志,综合应用地理信息系统、卫星遥感技术、全球定位系统、计算机、人工智能、信息技术,以及农业灌溉、气象学、系统工程等多学科的最新成果,提高调度的灵活性、可靠性、实用性,是灌溉实时调度今后的发展趋势。同时,也面临着基础设施落后、技术力量薄弱、信息处理费用过高、卫星传输周期长等多方面的困难。综述了国内外在实时灌溉预报、渠系动态配水、土壤墒情监测、计算机辅助决策支持系统以及灌区空间信息管理等方面的最新研究进展和主要成就,力求促进灌区用水管理研究的发展。  相似文献   

高分辨率卫星影像中阴影的自动提取与处理   总被引：27，自引：0，他引：27  

许妙忠  余志惠 《测绘信息与工程》2003,28(1):20-22

高分辨率卫星遥感影像开创了许多新的应用领域，但影像中的阴影是一个必须解决的问题。一方面，它给象影像分类这样的一些应用带来了很大麻烦，另一方面，它提供了物体的高度信息。本文利用纹理分析的方法，通过共生矩阵和相应指数的计算，对高分辨率卫影像中阴影的自动提取与处理作了一个尝试并给出了一些结果。  相似文献   

缺少控制点的卫星遥感对地目标定位   总被引：15，自引：2，他引：15  

袁修孝  张过 《武汉大学学报(信息科学版)》2003,28(5):505-509

从单线阵推扫式传感器的成像机理出发，利用6个卫星轨道开普勒参数和3个传感器姿态角建立了推扫式卫星遥感影像坐标与其地面点在地心坐标系下的坐标关系式，即构像方程。按照所建立的构像方程，对某地区一景SPOT-5影像进行对地目标定位，获得了实地上83．392m的平面精度；利用单个地面控制点对卫星轨道开普勒参数和传感器姿态实施调整后，目标定位精度提高到14．217m。试验证实，所建立的构像方程是正确的,在卫星遥感对地目标定位中有较好的应用前景。  相似文献