AERIAL CAMERA CALIBRATION

Abstract

Accidents will happen and the surveyor is therefore sometimes required to do the best he can with photographs taken with an uncalibrated camera which is not available for subsequent calibration. This note outlines a method by which an approximate principal distance can be obtained for high oblique air photographs from points appearing in the photographs.     

滤光片对航摄仪内方位元素、畸变差的影响

本文论述了滤光片的不平整度和光谱透射特性对航摄仪内方位元素、畸变差的影响,并对航摄仪不戴滤光片与戴滤光片做了对照检定实验,理论分析及实验结果都表明:滤光片对内方位元素、畸变差有较大影响,尤其对色像差较大的航摄仪,其影响更大。文章建议,航摄仪在检定时应加戴航摄时使用的滤光片。     

GPS辅助航摄仪内方位元素的测定

本文在简要介绍了ＧＰＳ辅助航摄仪内方位元素测定原理的基础上，给出了在太原航摄仪综合性能试验场对Ｗｉｌｄ ＲＣ－２０航摄仪进行动态检定的一组试验结果。试验证实文中所提出的两种ＧＰＳ辅助的内方位元素测定方法是正确和有效的。     

THE CALIBRATION OF AERIAL SURVEY CAMERAS

Two experimental procedures for aerial survey camera calibration using respectively a Wild TA theodolite and a modified Cooke, Trough ton and Simms geodetic theodolite are described. The procedures determine radial distortion only; tangential distortion is assumed to be negligible. Details of a graphical method of computing the results are given in an appendix.     

THE EFFECT OF GLASS COVER PLATES OVER CAMERA PORTS IN AIRCRAFT ON THE DISTORTION CHARACTERISTICS OF AERIAL SURVEY CAMERAS†

The effect of glass cover plates on the distortion characteristics of aerial survey cameras is shown to be relatively small. This fact supports the use of glass cover plates at high altitudes, as does the possibility of estimating and determining with sufficient certainty the systematic effect to be expected. If a decision is made against the use of glass cover plates, the effect of a variety of factors such as turbulence and temperature differences within the lens and the camera can hardly be estimated.     

AERIAL SURVEY: COLONY OF HONG KONG

This paper describes the planning and implementation of a very extensive aerial survey contract undertaken by Hunting Surveys on behalf of the Hong Kong Government. From photography carried out during January and February 1963, photogrammetric plotting at 1 : 600 and 1 : 1200 proceeded steadily over a period of 5 years to the point where all but the highest land in the Colony had been surveyed at one or other of these two large scales. The problems arising from the rather unique terrain conditions and the urban and industrial development of Hong Kong are dealt with mainly from the photographic and photogrammetric aspect but reference is made to the contribution of the Crown Lands and Survey Office of the Public Works Department of Hong Kong, who provided all ground control and undertook field verification.     

THE BENEFITS OF FORWARD MOTION COMPENSATION FOR AERIAL SURVEY PHOTOGRAPHY

Two of the speakers at a one-day symposium, held on 31st October, 1990 and concerned with the adoption of new equipment and techniques, comment on the introduction of forward motion compensation in air survey cameras and on a specification for architectural photogrammetry.     

航空遥感技术在新疆和硕-库尔勒段高速公路工程地质调查中的应用

在利用TM 图像进行区域工程地质条件分析的基础上,利用大比例尺航空像片,对新疆和硕-库尔勒段高速公路正线及比较线进行路线工程地质调查,并结合钻探、触探,探地雷达测试,对路线工程地质条件进行综合评价。     

AERIAL RECONNAISSANCE FOR TRIANGULATION

Abstract

Since 1929 much of the primary triangulation carried out by the Geodetic Service of Canada has been preceded by an aerial reconnaissance of the areas: during this reconnaissance a tentative selection is made of station sites, and likely lines of sight are indicated. Varied types of topography have been covered—mountainous, rolling, flat wooded, mountain valleys. In most cases there were three common factors: the areas were well watered with lakes and rivers which permitted low flying in safety with pontoonor skii-equipped planes, ground transportation was difficult, and no contour maps existed. In some of the areas existing maps were very incomplete; of a few, reconnaissance aerial maps were available in which the planimetry was good; the better the map the easier the aerial reconnaissance. In all cases it was considered necessary that the air operations be checked by ground visits to the tentatively selected stations.