共查询到20条相似文献，搜索用时 31 毫秒
1.
PENG Lin LIU Yanxiong ZHOU Xinghua WU Yongting 《地球空间信息科学学报》2006,9(2):99-102
IntroductionIn GPS data-processing, the most accurate andpopular method is to solve the unknown parametersbased on a GPS network which includes many GPSsites. This mode is always called network-solution.The network-solution makes use of the spatial geom-e… 相似文献
2.
XU Junfeng HUANG Jingfeng 《地球空间信息科学学报》2006,9(2):108-111
IKONOS image has been wildly used in city planning, precision agriculture and emergence response. However, the accuracy of IKONOS Geo product is limited due to distortion caused by terrain relief. Orthorectification was performed to remove the distortion and the impact of different DEM on orthorectification were evaluated. 38 ground control points （GCPs） and 25 independent check points （ICPs） were collected. DEMs were generated from 1 ： 10 000 and 1 ： 50 000 topographic maps. Results show that RMS error at the check points is 1. 554 0 m using DEM generated from 1 ： 10 000 topographic map, which can meet the accuracy requirement of IKONOS Precision product （1.9 m RMSE）. While RMS error is 2. 572 4 m using DEM generated from 1 ： 50 000 topographic map. 相似文献
3.
LIU Shaochuang LU Pingli LIU Donghui JIN Peidong Institute of Remote Sensing Applications Chinese Academy of Sciences Datun Road Chaoyang District Beijing China. 《地球空间信息科学学报》2007,10(1):51-56
For centuries, explorers and scientists from different countries had made their own conclusions on the source of the Mekong. However, the geographic source of the Mekong is still arguable because of the complexity of the Mekong source water system, inaccessible environment and the varied technologies used by those explorers and scientists. The satellite remote sensing technology has been used to pinpoint the source of the Mekong, associated with the on-the-spot investigations made by the authors in June 1999 and September 2002. The actual length of the Mekong has also been calculated. 相似文献
4.
5.
Andrew U. Frank 《Journal of Geographical Systems》2000,2(1):99-105
Geographical Information Science is essentially computational geography and has its own research program, namely all aspects
of formal models for spatial natural processes and the interaction of humans with the environment in space and time. This
is not a question of technology and technology-related research; but technology influences what questions can be researched
effectively. Collection of data in the field and the simulation of field experience through Virtual Reality are just two questions
of how spatial reality and human experience are linked. The focus on human spatial cognition is similarly found in software
engineering for interoperable Geographic Information Systems. 相似文献
6.
LIU Shaochuang LU Pingli LIU Donghui JIN Peidong 《地球空间信息科学学报》2007,10(1):51-56
For centuries, explorers and scientists from different countries had made their own conclusions on the source of the Mekong. However, the geographic source of the Mekong is still arguable because of the complexity of the Mekong source water system, inaccessible environment and the varied technologies used by those explorers and scientists. The satellite remote sensing technology has been used to pinpoint the source of the Mekong, associated with the on-the-spot investigations made by the authors in June 1999 and September 2002. The actual length of the Mekong has also been calculated. 相似文献
7.
In this paper,factors lead to changes ande what changes should be considered are firstly discussed.then changes to be represented by set theory is given.Twelve basic change types are described in detail.At last the paper points out that the change between geoobjects and pixels in images is not all corresponging and it causes the difficulty of accurate and robust change detection techniques. 相似文献
8.
Abstract The sensitivity of microwave sensors to changes in the complex dielectric constant of soil/water mix with change in water content has been used in several studies for soil moisture estimation and in the detection of wetlands. In the study, reported here, an attempt has been made to delineate various categories of wetlands, namely ‘bils’ (acquaculture ponds), lakes/ponds, creeks, and mangroves through visual interpretation of ERS‐1 SAR images acquired on 29th April, 1993 over part of Sundarban delta, abutting Bay of Bengal. An overall accuracy of 91.2% with respect to delineation of wetlands has been achieved. Further, the cloud penetration and day‐and‐night observation capability of ERS‐1 SAR, though well known, is also illustrated. 相似文献
9.
The multispectral and multitemporal analysis of the spectral response of rice has made it possible to determine at which point in the vegetative cycle of rice it is best to make an inventory, together with the usefulness of the normalized‐difference vegetation index for such an inventory. The results could be usefully included in any classification procedure of the TM image in order to make the inventory in a systematic way. In this case a supervised classification of the image has been made which assumes a Gaussian behaviour for each spectral class. The results obtained are, for the most part, consistent with those obtained by using traditional methods. 相似文献
10.
《地球空间信息科学学报》2002,(4)
1 .ＧｅｏｍａｔｉｃｓａｎｄＩｎｆｏｒｍａｔｉｏｎＳｃｉｅｎｃｅｏｆＷｕｈａｎＵｎｉｖｅｒｓｉｔｙ(Ｂｉｍｏｎｔｈｌｙ) ,ａｎａｃａｄｅｍｉｃｐｅｒｉｏｄｉｃａｌｏｒｉｇｉｎａｔｅｄｆｒｏｍＪｏｕｒｎａｌｏｆＷｕｈａｎＴｅｃｈｎｉｃａｌＵｎｉｖｅｒｓｉｔｙｏｆＳｕｒｖｅｙｉｎｇａｎｄＭａｐｐｉｎｇ ,ａｉｍｓａｔｅｘｔｅｎｄｉｎｇｉｎ ｔｅｒｎａｔｉｏｎａｌａｃａｄｅｍｉｃｅｘｃｈａｎｇｅｓｏｆａｄｖａｎｃｅｄｒｅｓｅａｒｃｈｒｅｓｕｌｔｓｉｎｓｕｒｖｅｙｉｎｇａｎｄｍａｐｐｉｎｇ .Ｉｔｃｏｖｅｒｓｔ… 相似文献
11.
ZHENGZhaobao 《地球空间信息科学学报》2002,5(1):1-6
In the photogrammetry,some researchers have applied genetic algorithms in aerial image texture classification and reducing hyper-spectrum remote sensing data.Genetic algorithm can rapidly find the solutions which are close to the optimal solution.But it is not easy to find the optimal solution.In order to solve the problem,a cooperative evolution idea integrating genetic algorithm and ant colony algorithm is presented in this paper.On the basis of the advantages of ant colony algorithm,this paper proposes the method integrating genetic algorithms and ant colony algorithm to overcome the drawback of genetic algorithms.Moreover,the paper takes designing texture classification masks of aerial images as an example to illustrate the integration theory and procedures. 相似文献
12.
Processing of Laser Scanner Data and Extraction of Structure Lines Using Methods of the Image Processing 总被引：3，自引：0，他引：3
SUILi-chun 《测绘学报》2004,33(1):63-70
激光扫描数据提供了一种新的手段用于获取高精度的数字地形表面模型. 原始的航空激光扫描数据表达的是一些非规则分布的"点云", 这些非规则分布的点需要进行有效的事后处理. 这种事后处理有2个目的:一是将那些分布在地表面上的点(即地面点)与分布在非地表面上的点(譬如树木、房屋或汽车上的点, 即非地面点)进行有效的分离;二是从分离后的地面点中提取结构线, 用于建立高精度的数字地面模型. 作者发展了一系列的基于数字形态学理论和稳健参数估计理论的方法用于分离和探测地面点. 这里所介绍和开发的提取结构线的算法建立在数字图像处理和表面曲率理论的基础上. 这些算法同样可以扩展地用于其他领域. 所介绍的基于数字图像处理理论处理原始的航空激光扫瞄数据和提取结构线的方法取得了很好的结果. 这一结论可以在本文中通过一系列的插图得到有力的证明. 相似文献
13.
LIN Xueyuan XU Jin ZHOU Min 《地球空间信息科学学报》2007,10(3):177-180
When SINS (strap-down inertial navigation system) is combined with GPS, the observability of the course angle is weak. Although the course angle error is improved to some extent through Kalman filtering, the course angle still assumes a divergent trend. This trend is aggravated further when using low-cost and low-accuracy SINS. In order to restrain this trend, a method that uses AHRS to substitute for SINS course angle information is put forward aimed at the hardware component characteristic of the low-cost and low-accuracy SINS including AHRS (attitude and heading reference system) and IMU (inertial measurement unit). Real static and dynamic experiments show that the method can restrain the divergent trend of the navigation system angle effectively, and the positioning accuracy is high. 相似文献
14.
CHENChujiang LIDeren ZHUQing 《地球空间信息科学学报》2005,8(1):33-38
This paper presents the studies of the refining of IKONOS-2 RPC, the transform of the datum, the mode of the control point distribution and the method of IKONOS stereo triangulation, so that IKONOS imagery can be used to collect the precise geospatial data and produce the large scale map. The transform between the IKONOS-2 image space and the national coordinate system based on the RPC have been developed, and the results of block adjustment with various control schemes in a practical project near Himalayas have been examined and analysed. The encouraging results of high positioning accuracy have been obtained. 相似文献
15.
16.
Paul W. Box 《Journal of Geographical Systems》2000,2(1):49-54
GIS and spatial analysis is suited mainly for static pictures of the landscape, but many of the processes that need exploring
are dynamic in nature. Dynamic processes can be complex when put in a spatial context; our ability to study such processes
will probably come with advances in understanding complex systems in general. Cellular automata and agent-based models are
two prime candidates for exploring complex spatial systems, but are difficult to implement. Innovative tools that help build
complex simulations will create larger user communities, who will probably find novel solutions for understanding complexity.
A significant source for such innovations is likely to be from the collective efforts of hobbyists and part-time programmers,
who have been dubbed “garage-band scientists” in the popular press. 相似文献
17.
XU Xiaohua LI Zhenghang LUO Jia 《地球空间信息科学学报》2006,9(1):13-17
Introduction WithGPSreceiversmountedonLEOsatel lites,GPSoccultationeventscanbeobserved.Theobservablesarevaluableforatmospheric monitoringandweatherforecasting.Whenpre paringtobuildupanLEOsatelliteoccultation observationsystem,theevaluation,designand imple… 相似文献
18.
《The Cartographic journal》2013,50(4):329-341
AbstractThe background and context to the cartography of the French military engineer Lewis Petit and his work in Scotland is explained. Petit was responsible for drafting the earliest plans and profiles of four castles in the north-west Highlands of Scotland (1714), as well as the earliest town plans of Perth and Inverness (1716). A consideration of their functions, particularly through the Board of Ordnance archives, allows a better understanding of these plans and their value as historical sources, as well as their accurate dating. Petit's work reflected national and international developments, including war in Europe and the Jacobite rebellions in Britain. His cartography illustrates the spread of new European military theories and practices, at a time when a professional corps of military engineers was being established in Great Britain. Through studying Petit and his maps we can gain a fuller understanding not only of the Board of Ordnance in Hanoverian Scotland, but also of the militarisation of cartography in the eighteenth century, and the emergence of standards relating to colour, scale and terminology. 相似文献
19.
GUO Tongde WANG Jiayao WANG Guangxia 《地球空间信息科学学报》2006,9(4):306-310
IntroductionCurves are the fundamental geometric elementsin GIS. The uncertainty of their positions has ani mportant influence on those outputs from GISandis the reliable basis for reasonably evaluatingthose outputs .In contrast to measurement error theor… 相似文献
20.
Tondozi Keto LIU Tianyou 《地球空间信息科学学报》2005,8(4):291-296
IntroductionGeophysics as its nameindicates has to do withthe physics of the earth and its surrounding at-mosphere . Gilbert’s discovery that the earth be-haves as a great and rather irregular magnet andNewton’s theory of gravitation may be said toconstitute the beginning of geophysics . Miningand the search of metals date from the earliestti mes , but the scientific record began with thepublicationin 1956 of the famous treatise De remetallica by Georgius Agricola , whichfor manyyears was … 相似文献