最新刊期
卷 ， 期 4 ， 2001
- 摘要：Direct space ground positioning system which is composed of Global Positioning System （GPS）, attitude measurement （i.e. inertial navigation system, INS） and laser scanning ranging is a new positioning technique developed in recent years, the system is one of the new methods which obtain geometric information of the terrain and generate digital elevation model for quantily of three dimensional remote sensing. This paper gives rigorous positioning equation and error transfer equation of air to ground positioning for airborne and space borne remote sensing. Error analysis of the system and precision evaluation based on the obtained equations for line scanning and circle scanning are given. The simulation computation indicates that the results of this paper have importance to practical application.关键词：GPS;attitude measurement;laser scanning ranging;positioning equation;error analysis;precision evaluation
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发布时间：2021-06-10 - 摘要：The entities in reality usually have indeterminate boundary and distribute continuously over space. They are fuzzy objects and cannot be represented by conventional field oriented or object oriented models in GISs. The authors propose the concept of “objects with fuzzy extents” to represent them. Three fuzzy object models are developed to represent fuzzy objects for different situations. The Fuzzy Fuzzy object （FF object） model represents objects that have an uncertain thematic description and an uncertain spatial extent, these objects may spatially overlap each other. The Fuzzy Crisp object （FC object） model represents objects with and uncertain spatial extent but a determined thematic content and the Crisp Fuzzy object （CF object） model represents objects with a crisp boundary but uncertain content. A practical example of coastal geomorphology study is elaborated to demonstrate the practical use of the proposed concepts and models.关键词：Fuzzy objects;data models;GIS;uncertainties
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发布时间：2021-06-10 - 摘要：In this paper, microwave radiation brightness temperature data from Special Sensor Microwave/Image （SSM/I） in America Defense Meteorological Satellite Program （DMSP） are used to conduct a study about China land surface temperature retrieval. SSM/I data selected was scanned on July 20 and 24, 1997. At first, the SSM/I data covering China land surface is processed and imaged. Then, types of the land surface are classified based on an algorithm described in Holliger’s report using the seven channels. At last, the retrieval of China land surface temperature is carried out by using a statistic method based on SSM/I multiple channel data. The result was validated by the retrieval of AVHRR brightness temperature data. There is a good trend between the result of SSM/I data and the result of AVHRR data. The result shows that SSM/I microwave radiometer data provides a fast study method to land surface temperature retrieval on a large area.关键词：special sensor, microwave/imager （SSM/I）;AVHRR;land surface types;Land surface temperature;Retrieval
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发布时间：2021-06-10 - 摘要：Change Vector Analysis （CVA） is a valuable approach for land use/cover change detection, in which how to determine change magnitude threshold and change direction reasonably is already becoming an obstacle for its widely use. Therefore, a new method named Double Windows Flexible Pace Searching is proposed in this paper aimed at determning change magnitude threshold reasonably and efficiently. As a result from the case study in Haidian District, Beijing, the accuracy of change detection is obtained about 87%, which indicates that the Double Windows Flexible Pace Searching method has potential utility in Change Vector Analysis for land use/cover change detection.
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发布时间：2021-06-10 - 摘要：It is important to solve the low performance of spatial vector data transmission in the client side Intermet GIS （Geographic Information System） which handles large size spatial geographic information on the Internet. This paper has proposed a new efficient method for it. The basic idea is that, firstly, a large size vector map is divided into several parts, where each part is called a ‘Tile’, according to an appropriate division granularity. Secondly, when an user requires a certain region in the map at client side, the GIS server only transmits spatial data in the tiles which overlap with the requested region. And the received data are stored in client local machine for reuse. For the support of this idea, a method of tile division, an algorithm for tile query processing and a strategy for efficient spatial data transmission between server side and client side have been provided. Comparing with the traditional methods of client side Internet GIS, the performance improvement is achieved by the usage of the proposed method.关键词：spatial data transmission;GIS;internet GIS;Spatial database
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发布时间：2021-06-10 - 摘要：The optimum variable selecting method on the forest volume quantitative estimation based on RS and GIS through the principle of least square is studied. The law of the variable selection on forest volume estimation is analyzed in detail by means of the real example, at the same time the predicting potentiality of forest volume through LS estimation is also discussed. The method has some guiding significances for the practical job.关键词：LS estimation;residual mean squares;forest volume
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发布时间：2021-06-10 - 摘要：In order to efficiently and accurately measure geographic locations of ground truth features in the field of resource and environment remote sensing using economical and easy operational GPS instrument, the following experiments were carried out using C/A code pseudodistance differential GPS instrument （DGPS）. Firstly, the effect of base station’s geocenter reference coordinate （WGS84） on location accuracy was evaluated. Secondly, a point was differentially located with a known trigonal control point as base station site and a three parameter Molodensky Model as datum transformation model between WGS84 and Beijing 54. On this point, we then established a temporal base station, which was used to measure the aimed ground truth features in the test site. The location accuracy attained by this route was evaluated as well. It was found that DGPS measured map is of highly absolute accuracy （2\5m）, and this absolute accuracy does not change with the minor error of georeference coordinate of the base station. It is a practical method to measure and establish a new temporal base station, which can be used to carry out the real measure work in the test site. The location error of this method is far under one image pixel size （25m） with one georeferenced TM image as evaluation reference. However, if the trigonal control point and datum transformation model do not exist, the result of base station single point absolute location can be used as reference coordinate, the measured result of which can be georeferenced to remote sensing image using some tiepoints on the basis of the first result above. Because this method does not need to know the georeference coordinate and datum transformation model, it’s a ecnomical and practical method for resources and environment remote sensing.关键词：DGPS;Pseudodistance differential GPS;datum transformation;resource and environment remote sensing;image geo-registration
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发布时间：2021-06-10 - 摘要：An algorithm for ship wake detection, based on Radon transformation and mathematical morphologic image processing （called as SWDRM） is developed. The important information from observation are kept in the inverted gray level image after being manipulated in Radon space. Ship detection can be achieved from a binary image. It is applied to automatic detection for ship moving from the SEASAT SAR images. The effect due to high level multiplied speckle noise is also discussed. The results show that this algorithm is well robust in noise presence, and is not very sensitive to the threshold parameters and the width of working window.关键词：radon transform;morphological image processing;ship wakes detection
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发布时间：2021-06-10 - 摘要：Aiming at remote sensing images of less ground reference point, we discuss a new geometric exact correction method in this paper. The method applies the theory of space map projection to geometric exact correction of remote sensing images, using spatial oblique mercator projection theory and a few ground reference points to do the geometry exact correction of images. The method is of strictness theory and rapidness arithmetic throughout the experiment of TM image of Guangzhou region, the precision of exact correction is less than one pixel.关键词：geometric exact correction;SOMP method;images with less ground reference points
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发布时间：2021-06-10 - 摘要：In this article, the principles and methods of the dust storm monitoring with multichannel image from the meteorological satellite are discussed. With the method, the 12 dust storm weather processes that affected a large area in the North China during the period of March to April of year of 2000 were monitored timely. With the analysis of monitoring data, it shows that the dust storm for Beijing region is mainly from the Inner Mongolia Autonomous Region and Hebei Province. They provide a valuable information for the government Department in planning for the dust storm prevention.关键词：duststorm;meteorological satellite
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发布时间：2021-06-10 - 摘要：It is the key for locating mineralized area with remote sensing technique to analyze the metallogenic geological environment and remote sensing information. It is very difficult to explore mineral resources in the high mountains where covered with glacier and snow. Through analysis of the geological setting, metallogenic environment and metallogenic marks, it has been well aware that the preferential target for remote sensing exploration is the hydrothermal vein type ore deposit which is located in the outer or inner contact zones of granite or granodiorite intrusion controlled by faults. The technique of Masking and Principal Component Analysis （MPCA） has been used to process the Landsat TM data, and the glacier and snow are masked. The MPCA 3,5,6 composite imagery shows the anomalous tone of limonnite and silicic alteration and the circular feature of granodiorite intrusive rock as well as the lens like structure in south of the circular image. The processed TM imagery has delineated the target for field investigation. At last, the Luobugaizigou polymetallic mineralized area is found.关键词：metallogenic environment;metallogenic mark;Mintiegai area;remote sensing exploration;polymetallic mineralized area
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发布时间：2021-06-10 - 摘要：This paper describes environmental conditions of Yigong landslide before it occurence and from the 4th to the 41st days during the landslide occurring. With multi temporal different satellite data, through digital image processing and precise registration with the topographic map for the landslide region, the color ortho images are formed. Based on the interpretation of these images, it is understood that the occurrence of Yigong landslide is a large scale gravity erosion activity in the process of Xi\|Ma\|La\|Ya Orogenic movement, and its activity style is “high speed debris flow landslide”. The entire debris flow body has been basically stable since the disaster happened, but the back end of the Zhanalong gully is still moving with the snow avalanche. The exposed area of the landslide has been varied in the limitation of 12.9\11.4 to 12.4\10.0km\+2 and the Yigong lake varied from 19.9 to 43.6 km\+2 during the 4th\41st days since landslide occurred. Owing to snow melting, the lake area became larger and larger quickly but the landslide dam was weak, it was thus deduced that the dam could burst at any time. It was bursted on Jun. 10, that conforms with the deducing result.关键词：satellite image;Yigong landslide;dam bursting
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发布时间：2021-06-10 - 摘要：Ground Penetrating Radar is an intact sounding technology in archaeological research field. It has constructive significance especially in positioning underground ancient relics or other remains and deciding the distribution area. The EMwaves can’not reach deep into the underground in the Yangtze downriver area because it is absorbed by plenty of moisture for the high underground water level and the wet earth. This fact results in the shorter penetrating altitude and less precision for the backwave shorter altitude and lower S/N rate. For the stratum is a kind of chromatic dispersion media, the radar backwave impulse become broader after it come across stratum. The backwave can be identified correctly and the precise position can be stated which make it difficult to define the project exact location and profile in the latter data processing and image rebuilding process. This article presents a new method that is encoded by both impulse signal and FMCW radar signal to positioning the underground ancient relics especially the vault tombs under the special geographic conditions like the Yangtze river. It increased the signal S/N rate by the vertical time related technology to enhance the penetrating precision. The profile of the underground tombs is determined by the way of backwave energy related method to indentify the project location. The wavetransmitting antenna is located at different places and the reflection character parameters of the project are processed in collective grouping way. Then using image processing technique the underground relics is reverselydeducted in 3D and the error of the position is deduced to the minimum.关键词：ground penetrating radar;application of underground remains;location of ancient relics;ancient tomb 3D reverse deduction
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发布时间：2021-06-10
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