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1.
During the summer of 1965, colour, false colour, infra-red and panchromatic photography was flown of the Breidamerkur Glacier area in south-east Iceland. Subsequent comparative interpretation studies of the film types have indicated that colour photography is superior for the interpretation of glacierized? areas. This is attributed to brightness qualities and a continuous colour tone range, which, in this instance, closely matched visual representation of ground objects. The false colour film, due to the striking tonal qualities of vegetation and moisture, is considered best for studies involving the delimitation of these features. Panchromatic film appears to be satisfactory for general interpretation work, particularly where the utmost in definition is called for. The infra-red film, because of the dark tones produced by gravels and the subsequent high contrasts between ice and gravel debris on the ice surface, is considered a poor choice for the interpretation of glacierized areas.  相似文献   

2.
The paper discusses aspects of air photography and electronic processes which produce imagery by infra-red radiation and by radar waves. After preliminary comments on lenses, laboratory techniques and colour photography, the author indicates certain advantages in simultaneous photography using black and white, infra-red and colour films. Moreover, information is given on simultaneous photography by satellite and the paper terminates with a resume of methods that are used to obtain imagery by infra-red radiation and by radar.  相似文献   

3.
CENSUS OF GREY SEALS BY AERIAL PHOTOGRAPHY   总被引:1,自引:0,他引:1  
The factors determining resolution in aerial photography of wildlife concentrations are considered and two developments that improve resolution with inexpensive equipment are described. Firstly, a rocking camera mount has been constructed that compensates for apparent image motion resulting from forward movement of the aircraft. The mount allows slower shutter speeds to be used so that aerial surveys can be conducted using high resolution colour film under poor light conditions. Secondly, critical prefocusing to the survey flying height is carried out, even for lenses of short focal length. Aerial photography of grey seal breeding colonies is used to illustrate these developments.  相似文献   

4.
In August 1966 aerial photography, using five film/filter combinations, was obtained of the Dyfi Estuary, on the coast of Cardigan Bay. The paper discusses some of the problems associated with a project involving several emulsions and in which photography of the inter tidal area must be achieved as near low water as possible. Preliminary results confirm that, in general, colour and false colour photographs improve both the speed and reliability of interpretation when compared to monochrome photographs.  相似文献   

5.
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   

6.
The properties governing the choice of sensitised materials for air photography are discussed, and reference is made to the practical problems of obtaining optimum quality in the negative. Two new methods of processing air films are discussed. The merits of air photography in colour are briefly reviewed.  相似文献   

7.
A study of coastal marshland using panchromatic vertical aerial photography suggested that October was the best season of the year for the interpretation of vegetation while February was most suitable for examining topographical or pedological features. False colour film was used to isolate certain plants from bare mudflats where it was impossible to identify these by differences in texture or height.  相似文献   

8.
An attempt is made to review the factors affecting the use of colour photography in photogrammetry and photo-interpretation. Examples of current practice and results of comparative tests are quoted, as well as the advantages and deficiencies of the various materials available.  相似文献   

9.
A technique which enables spatial data to be obtained from historical photography is outlined. The method is applied to a 40 year sequence of oblique aerial photography of the Black Ven landslide in Dorset, England. Some of the possible data processing options are discussed and illustrated by some preliminary results produced from the Dorset landslide.  相似文献   

10.
Abstract

This paper investigates the combination of metric aerial photography and near‐infrared (NIR) videography data to improve the design of field‐survey sampling frameworks. Spatial data collection can contribute up to 80% of the cost of deploying a Geographic Information System (GIS) based Decision Support System (DSS). The use of remotely sensed information, field survey using differential Global Positioning System (dGPS) and geostatistical interpolation methods maximises data quality for a given rate of sampling.

Medium‐format colour aerial photography and NIR videography were orthorectified to the national map base and mosaiced using ERDAS Imagine. The green and red layers of the aerial photography were combined with the NIR videography to form a false‐colour composite image. Two sampling strategies were tested. The first stratified sampling on a per field basis, creating four points per hectare, randomly located within each field. The second strategy used the remotely sensed information to identify within‐field variability classes for each field, using red‐green difference or normalised difference vegetation index (NDVI) models. These variability classes were used as a sub‐stratification framework with each class sampled at the same rate of 4 per hectare. For both strategies the sample points were generated within ESRI ArcView and were located in the field using dGPS. Maps of stone content were created using geostatistical methods and validated against samples collected on a 100 metre grid. It was concluded that combining the two image sources to create a within‐field stratification framework improved the precision of the results obtained from field‐survey.  相似文献   

11.
The first author commenced his experiences with aerial photography in 1945, when he joined the Royal Air Force (RAF). The aerial cameras used at that time were the Williamson F24 and F52, with Ilford HP3 and FP3 panchromatic films. Subsequently the Williamson F95 camera was tested against the USAF Sonne 11 camera. During his final years in the RAF, a variety of film types was employed: colour, monochrome infra-red and false colour infra-red. Additional experience was gained when the author was employed by the International Training Centre (ITC), The Netherlands and he saw the further development of the air camera from the Wild RC8 and Zeiss (Oberkochen) RMK 15/23 to the Wild RC20, Zeiss (Jena) LMK and Zeiss (Oberkochen) RMK TOP. He predicts that the future lies with digital cameras.
The second author started working with aerial photography in the 1950s. Details are given of cameras, visual navigation sights and survey aircraft dating from that period. Overseas operations, carried out mainly by Hunting Surveys and Fairey Surveys, posed particular problems because the majority of the work there was undertaken without the aid of existing maps. The introduction of external navigation systems is described, from the Decca ship navigation system, through the GNS-200 VLF/Omega low frequency radio system to INS, the Inertial Navigation System. The author later joined the ITC, which enabled him to participate in trials of the Computer-controlled Photo Navigation System. Eventually practical experience was gained with differential GPS, particularly in countries in southeast Asia. Aerial photography currently appears to benefit less from financial investment than the photographic, aviation and survey industries. However, the satisfaction of making a significant contribution to major overseas development projects outweighs the frustration of lack of acceptance of plans for the future of the air survey industry.  相似文献   

12.
The colour photograph requirements of the photogrammetrist and the photo-interpreter are not always compatible. The author puts forward suggestions for improving the quality and reducing the cost of photography for interpretation purposes, based on the use of 70 mm film cameras. He found supporting evidence for this point of view during his visit to the United States as the result of the award of a Winston Churchill Fellowship in 1969.  相似文献   

13.
拟议中的南水北调中线工程,南起长江三峡水库,横跨长江、淮河、黄河及海河流域,全长1600km,是一项跨流域远距离调水,改变祖国面貌的宏伟工程。自50年代起,该项工程就开始了规划,并对其可行性进行了多方面科学论证和研究。1984年地矿部地质遥感中心沿黄河至北京段进行了1:2万彩红外航空摄影,为河北段进行遥感解译试点工作提供了先决条件。本次工作选择河北段长470km,面积18,916km2进行遥感水文工程地质解译,取得了成功。  相似文献   

14.
15.
车载移动测量系统可以快速、高精度地对测区进行三维激光扫描,但是因地物遮挡、视角限制,使得点云数据存在缺失;无人机航测具有高效率、高灵活性和低成本等优势,但是稳定性差,受天气影像严重,易导致影像不清晰或精度低。无人机航测技术可以弥补车载移动测量技术的采集盲区,后者可以发挥高精度的优点,二者技术联合应用,将极大提高测绘精度及生产效率。本文以某小区为例,进行了相关方法实验,对建筑物顶部或植被茂密处等扫描盲区,采用无人机航测补测,通过高精度激光点云对航摄影像进行纠正匹配,综合利用激光点云与航摄影像进行大比例尺测图。  相似文献   

16.
阐述了利用无人机搭载佳能EOS 5D MarkⅢ相机获取的航摄影像数据,在像素工厂下制作DOM的全过程,着重讲解了空三加密处理流程,总结了需要注意的问题,可为今后相关数据的生产提供参考。  相似文献   

17.
应用陆地卫星TM、MSS图像、航空彩红外像片、红外细分光谱扫描数字图像等多种遥感图像,结合多源信息复合处理技术,在甘肃安西北部地区(北山南带西段)开展了1:5万遥感地质调查和以金、铀为主的遥感找矿预测。通过工作,在合理应用综合遥感技术方法、基础地质研究、金铀矿产预测,以及1:5万遥感地质成图方法研究等方面均取得了重大进展。三年中,11人共编测了1:5万遥感地质图和1:5万遥感成矿预测图各21幅,解译发现了近千条蚀变岩带,圈出了67个金矿找矿靶区和铀成矿远景区,为开辟找矿新区提供了大量新的重要依据。  相似文献   

18.
Over the past ten years, Photarc Surveys Limited has been taking aerial photography from a low flying helicopter to determine road surface spot heights. Developments in technology over this period have resulted in investigations into improvements in this technique and, in particular, in the provision of control for the photography. This paper represents the preliminary investigations into the problem of providing control for the photography including some experiences of using an inflight control system.  相似文献   

19.
光学卫星摄影无控定位精度分析   总被引:4,自引:2,他引:2  
王任享  王建荣  胡莘 《测绘学报》2017,46(3):332-337
"全球连续覆盖"和"局部区域覆盖"是卫星摄影测量常用的两种摄影模式,两种模式应用目标和无控定位实现途径也各有特点。本文简要介绍了两种模式典型的卫星无控定位精度情况,阐述了光束法平差的关键技术,重点对前方交会和光束法平差无控定位精度进行试验分析。试验结果表明,姿态误差是影响无控定位精度的重要因素,影像分辨率对其影响较小。当外方位角元素误差大于0.5″时,即使影像分辨率为5m,光束法平差后,其无控定位精度也优于0.5m分辨率影像前方交会精度。  相似文献   

20.
倾斜摄影实景三维建模技术将传统测量从二维平面提升至三维立体层次,同时也将部分外业测绘工作转化到内业数据处理,极大程度地提高了生产效率.作为一种新兴测绘技术,倾斜摄影实景三维建模技术具有其自身的两面性,本文从倾斜摄影实景三维建模技术原理出发,结合其优点及不足之处,详细阐述分析了该技术在各个领域的应用现状及优化措施.  相似文献   

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