普通变焦数码相机快速标定方法

普通数码相机在近景摄影测量中的应用日益广泛,其标定方法备受关注。本文在传统的胶片相机标定方法的基础上,提出了一种可用于普通数码相机在焦距变化情况下的快速标定方法,并通过实验证明了该方法的可行性。     

基于DLT模型的一种数码相机检校方法

直接线性模型法是相机检校中常用的一种方法，在其基础上提出了一种适合计算机处理的数码相机检校方法，其通过改变像方元素的单位，就可使用现有的摄影测量程序直接处理数字影像。文中进一步讨论了像素尺寸大小对系统误差的影响，并对像素大小的必要测定精度进行了公式推导。最后的实验结果表明，该方法可以获得较好的校准结果。     

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.     

A NEW LIGHTWEIGHT CAMERA RIG

A new lightweight vertical camera rig which can be clamped to the front legs of the front seat of a light aircraft is described. In one version, a fixed transparent fairing is attached to the door, whereas in the second version the fairing is attached to the camera rig itself which can then be extended and retracted in flight. This rig has received C.A.A. (Civil Aviation Authority) Approval.     

MEDICAL APPLICATIONS OF CLOSE RANGE PHOTOGRAMMETRY

With the advent of powerful computers and cheap optical devices, photogrammetric methods are now being used in several aspects of medicine. The application of close range photogrammetry to human movement analysis and body shape measurement is described.     

CLOSE RANGE MEASUREMENT USING ELECTRONIC THEODOLITE SYSTEMS

Co-ordinate measuring systems based on theodolites are increasingly being found in industrial environments. The paper explains the principles on which the technique is based, the system components and the factors which affect the accuracy that can be achieved. Finally some application areas are listed and a particular example from the aircraft industry is highlighted.     

IS THERE A FUTURE FOR FILM IN CLOSE RANGE PHOTOGRAMMETRY?

Preliminary results of an investigation to study the dimensional reliability and potential of small format film products, allied with their use in small format cameras for photogrammetry, are presented. Investigations included analysis of factors influencing both in plane and out of plane deformations. Experiments were conducted using commercially available 70 mm, 120 and 220 film products, processed according to manufacturers’recommendations. Elements of camera design are discussed in the light of results obtained from the measurement of réseau images produced from a modified Hasselblad SWC camera.     

AN APPLICATION OF CLOSE RANGE PHOTOGRAMMETRY IN SHIPBUILDING

A test was devised to measure the distortion of a ship section during and after a crane lift. As the shipbuilders expend significant man hours and costs in carrying out adjustments to fit ship sections together after lifting, it was hoped that information gained from the test could be used to make design adjustments to ensure a better fit. The test was carried out by BKS Surveys Ltd. and Harland and Wolff Ltd., the Belfast shipbuilders.     

古建筑高精度正射影像图的制作

提出了基于分层三角网的在及物体之间遮挡关系，同时引入相对控制条件，使用纹理贴面技术制作高精度正射影像的方法和实现技术。在VirtuoZo数字摄影测量软件中据此开发了相应软件模块，从而实现了香港志莲净苑大雄殿正立面影像图的制作。     

数字近景摄影测量在古建筑物重建中的应用研究

讨论了一种建立古建筑复杂表面构件的三维模型的方法.在工程作业现场,用数码相机 PC机 摄影测量软件 CAD的方法建立复杂构件的DSM.实践证明,这种方法是非常有效的.     

MEASUREMENT OF SURFACE ROUGHNESS IN DESERT TERRAIN BY CLOSE RANGE PHOTOGRAMMETRY

As part of the measurements of desert terrain characteristics in the United Arab Emirates, made in support of a study of airborne radar, close range vertical stereophotographs of various natural surfaces were taken with a pair of Hasselblad MK70 metric cameras. The technique is described and the constraints imposed by the ground conditions and the need for rapid measurements are explained. Various terrain types are illustrated and the method is described whereby variables summarising surface roughness and surface slope were generated from profiles of the microrelief. From a more general discussion of current equipment and geomorphological applications of close range photogrammetry, it is concluded that this flexible technique is presently under utilised by field scientists.