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1.
The author discusses factors which affect satellite imaging systems and in particular the qualities of the Metric Camera and Large Format Camera photography.  相似文献   

2.
Metric Camera photography has been examined by the Hydrographic Department to assess its potential in nautical chart compilation and revision. Some interesting benefits are reported in the positioning and delineation of offshore features.  相似文献   

3.
The Ordnance Survey of Great Britain (OS) is a Principal Investigator for the Metric Camera experiment being organised by the European Space Agency (ESA). Two investigations are being conducted by the OS, both concerned with the potential value of the photography for topographic mapping and map revision. The first relates to Great Britain and the second relates to the developing countries of the world. Neither of these investigations is complete and only interim results and conclusions can be presented.  相似文献   

4.
This study reviews Metric Camera photography as a data source for land resource evaluation. It concludes that the system is a major move forward in the field of remote sensing and draws particular attention to the value of the stereoscopic image as an aid to interpretation of the data.  相似文献   

5.
The Metric Camera workshop was held to discuss results obtained from experiences carried out by principal investigations in the Metric Camera Project. The papers divided into three groups: photogrammetric investigations, interpretation and general. The photogrammetric investigations covered tests of accuracy. Plotting, aerial triangulation and the production of digital elevation modles and orthophotographs. There was general agreement that planimetric accuracies of between 20 m and 30 m and height accuracies of about 30 m could be achieved The emphasis within the group of papers on interpretation was on geology and the maping of cultural features. Results of this work are summarised and discussed in this paper.  相似文献   

6.
分析了数字摄影测量相机(DMC)在航空摄影测量及大比例尺数字化成图中遇到的问题,如摄影比例尺的选择;数字解析空中三角测量野外像控点间航向基线数、旁向航线数、区域网总航线数的确定;摄影测量平台软件的选择;对计算机硬件的要求;摄影精度、加密精度、成图精度等.  相似文献   

7.
A short review is given of the involvement of the Institut Géographique National (IGN) in the European Space Agency Spacelab Metric Camera (MC) experiment. IGN has participated in this project from the early stages of its preparation in 1974. The assessment of MC data has been carried out for both metric and thematic purposes. Using a Matra Traster analytical plotter, a contoured map of Carpentras. included in the European standard test site of Marseille, has been prepared at a scale of 1:100 000 with 100 m and 50 m contour intervals. Preliminary comparison of this map with the topographic data base shows a height accuracy of about 30 m. Orthophotographs have been produced of the same area, at 1:100000 scale and at 1:250000 scale. showing good agreement with the basic line map. An infrared colour pseudo-orthophotograph has been produced for Khartoum (assuming that the ground was flat) and a space map of a desert area of Algeria has been printed at 1:200000 scale, allowing a good comparison with the drainage shown on the existing line map. Interpretation of the MC photography has also been assessed and compared with conventional IGN aerial photography taken over the European standard test site. Due to the low sun elevation and the apparent image motion which affected the MC photography, the result is not as good as was expected. Some linear features of 6m width are visible (for example, roads and hedges) but for positive identification a width of 18m is necessary. It is difficult to determine the extent of cities and land parcels less than 40 × 40m are not visible. However, the MC data can be used for checking and revising some features of small scale maps (smaller than 1:100000). Two experiments have been performed in thematic interpretation, one concerned with land use and the other with forest mapping. Some improvements of the MC are suggested in order to satisfy the major requirements of users while the possibilities of topographic mapping from these data are summarised.  相似文献   

8.
本文论述了空间实验室测量相机(MC)拍摄的彩色红外立体像对在中比例尺地形制图、正射影像地图以及土地资源调查中的应用可能性,给出1:10万和1:20万比例尺的制图例证,表明平面位置和高程精度能满足1:10万比例尺地形图规范要求;1:10万比例尺影像图可以满足专题制图精度要求。 应用数字图像处理技术,将二种来源(MC,MSS)的遥感数据做数字匹配,并进行信息提取、组合、增强和分类等处理,其结果与原始图像比较表明有独特的优越性,与MSS原始数据相比,图像的空间分辨率明显提高,各种类型界线更分明,可分辨类目增多;而与MC原始图像相比,其光谱特性获得改善且能保持原有的空间分辨率。土地利用类型解释精度与MSS和MC原始图像比较分别提高7—20％左右。  相似文献   

9.
The paper presents an assessment of the results of a practical investigation into topographic interpretation from photography taken from the Spacelab Mission launched on 28th November, 1983. Hunting Surveys Ltd. had carried out mapping at 1:100 000 scale of part of Oman from photography taken in 1981 and stereoscopic cover of this area from Spacelab was available, so providing the opportunity of a comparison of the interpretation with the existing mapping.  相似文献   

10.
The accuracy of heighting from Large Format Camera (LFC) stereo-photographs of the New England area was evaluated using a conventional mirror stereoscope equipped with × 6 binocular eyepieces and a precision parallax bar. It was discovered that a large differential ω had to be removed before acceptable height results could be obtained. Enlarged portions of the LFC photographs covering city areas of Boston, Massachusetts and Providence, Rhode Island could be used to produce accurate height results. It was concluded that analogue mapping from LFC photography using simple instruments could be economically carried out at a scale of 1:100000 or smaller, with a contour interval of 100 m to 120 m.  相似文献   

11.
Rigorous photogrammetric methods have been used to carry out a detailed evaluation of Metric Camera panchromatic photographs of two areas, one in south-east France and the other on the coast of Libya. Inner, relative and absolute orientation and space resection were performed in order to determine how accurately ground co-ordinates can be obtained and the most suitable scale for mapping. Results of absolute orientation (residuals of 19m in plan and 26m in height) indicate that it is possible to produce maps at 1:100000 scale with contours at 100m intervals. Plotting has been done at 1:100000 scale showing cultural and drainage features. It was not possible to identify all detail which is plotted on existing 1:100000 scale line maps.  相似文献   

12.
PREFACE There are various publications on the 90th birthday of Gottfried Konecny.His involvement in the International Society for Photogrammetry and Remote Sensing(ISPRS)is particularly described by others.Here,his forward-oriented impulses in research and development at the former Institute for Photogrammetry and Engineering Survey of the(Technical)University of Hannover,today Institute for Photogrammetry and Geoinformation,Leibniz University Hannover,and some of his activities supporting developing and other countries by given short-term courses are highlighted.Gottfried Konecny was always one of the first in pushing new technologies.With the analytical plotter AP/C-3,he introduced analytical photogrammetry in Germany.Based on his experience with this not really operational version,he induced the company Zeiss to develop the first really operational analytical plotter Planicomp,which resulted in the end of analog photogrammetric devices and their limitations.At the invitation of Gilbert Hobrough,a mainly hardware-based image correlator was developed for the AP/C-3 in Hannover which anticipated many of today's applications.Gottfried Konecny initiated remote sensing in Germany.Based on his proposal with the Metric Camera Flight on Spacelab,the then highest resolution civil stereoscopic space images available were generated.Despite limited computer performance at his institute,a digital stereo plotter was developed,using hardware components from the cooperating Swedish company Context Vision,long before digital stereo workstations with increased and affordable computer capacity were possible.Also,in the area of GIS,he too,pushed development in collaboration with companies and administrations.Shortly before the end of his time as head of the institute,and more so after he became emeritus professor,he started a series of educational workshops,particularly in developing countries,but also other countries,to support the development of photogram-metry,remote sensing and GIS.He promoted the use of space imagery for mapping to improve the situation of poorly updated topographic maps.  相似文献   

13.
Following the success of the symposium held by the Photogrammetric Society on 31st March, 1987, a second one-day symposium was convened to give further support to the rapidly growing interest in the development of small format photography for aerial survey. This was held at Burlington House, London on 1st November, 1988. Over 70 people attended. Six of the papers are reproduced here, dealing with a range of topics including specifications for and navigation of small format aerial photography, the creation of digital terrain models from 35 mm photography, wildlife surveys in the Arctic and survey photography from model aircraft and tethered balloons.  相似文献   

14.
The Air Photographs Unit of the Royal Commission on the Historical Monuments of England (RCHM) has taken a large collection of oblique aerial photographs, using a non-metric camera, of archaeological evidence. Techniques are described which use this photography in conjunction with a Kern DSR1 analytical plotter to produce maps. Some results from using the techniques are given.  相似文献   

15.
清晰度是反映影像质量的重要因素。首先对遥感影像的清晰度评价方法进行了总结,重点介绍了平均梯度、灰度-梯度共生矩阵和Q指数3种方法,并通过大量测试比较了3种方法的优劣。实验结果表明,Q指数要明显优于前2种方法,是一个较好的遥感影像清晰度评价指标。  相似文献   

16.
The paper entitled The Photogrammetric Society Analogue Instrument Project was published in The Photogrammetric Record 14(82): 565-582 (October 1993). Extracts have appeared in each subsequent issue such that all the standard types of analogue instruments mentioned in the catalogue have now been included, some 28 instruments in all. In this final extract, the three remaining instruments listed in the catalogue are dealt with. All are of a type usually known as approximate solution instruments because they did not attempt any form of accurate space intersection but relied on applying a number of corrections to a model formed on the assumption that the photographs being used were true verticals taken at the same altitude. The accuracies achieved by such instruments depended both on how close the photography being used was to this ideal situation and on the degree of sophistication in the design of the analogue correctors incorporated in any particular instrument. The raison d'être for such a genre of instrument was essentially one of cost. Any organization faced with the requirement to produce small scale topographic mapping of an extensive region within a reasonable period of time might consider spending its available funds on a larger number of cheaper approximate solution instruments, always provided that an acceptable degree of accuracy could be maintained. Fortunately for such projects the specification would normally be for mapping of a graphical order of accuracy produced from high altitude photography. At such altitudes, stable flying conditions and small camera tilts of the order of 3° to 4° could realistically be expected. However, to obtain the best possible results from such photography, the best images possible should be provided for the operator, a factor sometimes overlooked by some manufacturers in their attempts to produce cheaper instruments. In view of the background to the development of British photogrammetry mentioned in previous extracts, it is perhaps surprising that a successful instrument of this type was not produced in the UK at a much earlier point in the era of analogue photogrammetry. Approximate methods were certainly favoured and promoted but only as far as planimetric maps were concerned. For these, form lines rather than contours were drawn when height information was considered necessary. However, when it was finally produced, the Thompson CP1 (manufactured by Cartographic Engineering Ltd.) proved to be an excellent instrument of its type and less approximate in its solution than most of its competitors. The other two instruments described in this extract are the Zeiss Stereotope and the Galileo-Santoni Stereomicrometer. The instruments are introduced in the order of their appearance on the market, which is also the order of the degree of sophistication found in the analogue computers they employed to reduce the errors introduced by any camera and airbase tilt present in the photography.  相似文献   

17.
The introduction of digital cameras for aerial survey photography and use of scanners with processed aerial film present a number of technical questions concerning the way photography is to be acquired in the future. Among the questions to be addressed are the comparative metric properties of images acquired by each system and the associated image quality characteristics. The new digital camera systems will require very careful appraisal, using well-established methods of assessing metric quality already available to survey organisations. The questions concerning image quality are more difficult to answer, as they require very specialised instrumentation if measurements are to be made directly in practice. Over the course of the past several decades a more analytical approach to assessing image quality has emerged, and one that may be used by individuals. The method is particularly effective where information on the micro-image characteristics of products is made available by the manufacturers concerned. An outline is given of some considerations that need to be taken into account when using an analytical approach, with references given for further reading.  相似文献   

18.
The development of the National Aeronautics and Space Administration's Large Format Camera has added a new dimension to remote sensing. Offering inexpensive large area coverage imagery with excellent geometric fidelity, the LFC was successfully flown in late 1984 aboard the Space Shuttle. The success of this initial flight has encouraged scientists to propose that the LFC be included as part of the earth observation sensor bed on the planned space station.

The relatively low costs associated with LFC photography provide an opportunity for developing countries to learn more about the capabilities and advantages of exploiting remotely sensed imagery. In particular, by using LFC imagery to study an array of local and global phenomena, these developing countries can quickly increase their knowledge of earth observation techniques and join the “community”; of nations currently active in remote sensing efforts.  相似文献   

19.
The major contribution of this paper relates to the practical advantages of combining Ground Control Points (GCPs), Ground Control Lines (GCLs) and orbital data to estimate the exterior orientation parameters of images collected by CBERS-2B (China–Brazil Earth Resources Satellite) HRC (High-resolution Camera) and CCD (High-resolution CCD Camera) sensors. Although the CBERS-2B is no longer operational, its images are still being used in Brazil, and the next generations of the CBERS satellite will have sensors with similar technical features, which motivates the study presented in this paper. The mathematical models that relate the object and image spaces are based on collinearity (for points) and coplanarity (for lines) conditions. These models were created in an in-house developed software package called TMS (Triangulation with Multiple Sensors) with multi-feature control (GCPs and GCLs). Experiments on a block of four CBERS-2B HRC images and on one CBERS-2B CCD image were performed using both models. It was observed that the combination of GCPs and GCLs provided better bundle block adjustment results than conventional bundle adjustment using only GCPs. The results also demonstrate the advantages of using primarily orbital data when the number of control entities is reduced.  相似文献   

20.
Pictometry倾斜摄影技术及其在3维城市建模中的应用   总被引：4，自引：0，他引：4  
倾斜摄影技术是国际测绘领域近些年发展起来的一项高新技术.它颠覆了以往正射影像只能从垂直角度拍摄的局限,通过在同一飞行平台上搭载多台传感器,同时从一个垂直、四个倾斜等五个不同的角度采集影像,将用户引入了符合人眼视觉的真实直观世界.倾斜影像技术的引进和应用,使得目前高昂的3维城市建模成本将得以大大降低.由于倾斜影像为用户提...  相似文献   

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