THE EVOLUTION OF DIGITALPHOTOGRAMMETRYFROM ANALYTICAL PHOTOGRAMMETRY

The evolution of digital photogrammetry from analytical photogrammetry is outlined, partly by considering the methods employed, but with the main emphasis on mathematical and physical principles. A fundamental distinction is obvious from the nature of the primary information measurement data: the image co-ordinates with analytical photogrammetry and the digital image grey values with digital photogrammetry. For both techniques, appropriate Gauss-Markov evaluation procedures are compared. The relevant relationships between image space data and object space models are presented; radiometric considerations play a more important role than before. The evaluation of digital image grey value data is no longer based on digital image correlation. Instead, a new principle of image inversion has been introduced by directly back-projecting grey values of an image on to object space models. The numerical procedures of digital photogrammetry need some stabilisation by appropriate regularisation elements. The new concept of digital photogrammetry may be applied to imagery from almost any sensor.     

THE CONVERSION OF CO-ORDINATES FROM THE CASSINI TO THE TRANSVERSE MERCATOR PROJECTION

Abstract

1. The Secondary and Tertiary Triangulations of the six counties of Northern Ireland which were observed about 1900 were computed county by county each on its own meridian on a Cassini projection using Airy's figure of the earth. Although a number of points common to two or more counties were fixed no attempt was made to bring the separate counties into sympathy either with each other or even with the old Primary triangulation as adjusted by Clarke in 1856.     

X-RAY PHOTOGRAMMETRY OF ARTIFICIAL JOINTS

X-ray photogrammetry has the potential to make a significant contribution to clinical orthopaedic practice. The features of X-ray photogrammetry as it can be applied in the clinical setting are reviewed, together with some of the analytical methods of three dimensional reconstruction. A major effort in orthopaedics involves the further improvement in the durability of artificial hip joints, whose ultimate life is usually limited by loosening of the components within the bone. Current methods of assessment are described and a review presented of X-ray photogrammetry of the hip. It is believed that a proposed system at Oxford combines the best features of earlier methods. Some possible developments of X-ray photogrammetry in orthopaedics are suggested.     

THE CURRENT INVOLVEMENT OF IGN IN PHOTOGRAMMETRY

A review of some recent activities undertaken by the Institut Géographique National, France (IGN) in photogrammetry is given in this paper, especially with regard to digital and space data processing, assessment of SPOT images and the development of new instruments and experimental map products. The main topics considered can be divided into three groups: aerial surveying, digital photogrammetry and space photogrammetry (including the possibility of further planetary missions).     

THE RECORDING OF SOME PREHISTORIC CARVINGS AT STONEHENGE

Non-topographic photogrammetry is often of interest because of unusual fields of application. A recently designed Galileo-Santoni stereometric camera has been used to photograph carvings made approximately 3500 years ago. A contour plot has provided the archaeologist with a permanent and quantitative record.     

AN INVESTIGATION INTO THE COMPUTATIONAL PROCEDURES OF SPACE RESECTION BY COLLINEARITY EQUATIONS

Space resection with collinearity equations is an elementary task in computational photogrammetry. However, two confusing issues associated with this process were identified from past teaching experiences in a third year university level course of analytical photogrammetry, These two issues, namely the formulation of observation equations and the performance of least squares adjustment, are discussed. Numerical examples are provided for illustration.     

UNDERWATER PHOTOGRAMMETRY IN THE NORTH SEA

Underwater photogrammetry is being used in the particularly hostile environment of the North Sea where it has been put into commercially viable operation. The authors discuss underwater photogrammetry related to other means of inspection of oil platforms. They also deal with operational experience of 35 mm and 70 mm cameras, camera calibration, the provision of control and photogrammetric observations and data analysis. The demand for underwater photogrammetry continues to grow.     

航空遥感在佛山城市空间环境质量评价中的应用

本文主要介绍利用佛山市航空遥感综合调查资料分析城市环境的空间结构，建立了空间结构分类系统，探讨了城市形态的变化，综合评价城市空间环境质量，并提出一些改善环境质量的建议．     

HIGH PRECISION PHOTOGRAMMETRIC MONITORING OF THE DEFORMATION OF A STEEL BRIDGE

Site procedures, instrumentation, analytical methods and accuracies achieved are described for the measurement of the deformation of a military steel bridge under load in a test gantry. Some remarks concerning the advantages and disadvantages of photogrammetry as a method of industrial measurement are made.     

The Digital National Framework and Digital Photogrammetry at Ordnance Survey

Over recent months the Ordnance Survey, Britain's national mapping agency, has changed the way in which it uses photogrammetry to update its large scales topographic database. The nature of the database itself has also changed during the same period, as the concept of a "Digital National Framework" has developed. This paper describes the Digital National Framework, the topographic data captured by Ordnance Survey within this framework and the capture methods currently used. The paper concentrates on the use of photogrammetry in the update process, describing the methods of the past, the methods currently in production, and the outlook for photogrammetry within the Ordnance Survey in future.     

三角形约束下影像匹配的算法实现

针对三角形约束下影像匹配方法的实际应用,分析了所采用的数据结构与Delaunay三角网动态更新,提出了一种高效的实现算法,实际应用验证了其实现的有效性。     

FURTHER DEVELOPMENTS IN THE PHOTO-RADIATION METHOD OF TERRESTRIAL PHOTOGRAMMETRY

The photo-radiation method of terrestrial photogrammetry was introduced in 1981 as an appropriate means of rapidly surveying large areas of open ground, primarily beaches. Since that time, several variations on the standard method have been tested. These have arisen from attempting to solve problems associated with particular situations. For instance, the use of the waterline as a means of contouring developed from a problem where a dangerous river bank was inaccessible for traditional survey observations. Another application concerned laboratory testing where photogrammetry is particularly attractive for measurement due to the coverage which is possible, together with the advantage that permanent records remain on film for later re-analysis. Both these variations in the photo-radiation method are described, together with an indication of the circumstances under which they have been successfully applied.     

我国文物考古近景摄影测量的现状和展望

本文在阐述我国考古测绘现状的同时,列举实例说明了近景摄影测量是考古测绘最理想的方法,并展望了其发展方向。     

机载POS直接地理定位软件AeroDG的设计与实现

AeroDG是专门针对机载POS直接地理定位方法而设计开发的数据处理软件。本文从软件的功能需求入手，重点讨论了软件的 设计思路和关键技术，同时详细介绍了软件实现的主要功能。     

A METHOD OF OBTAINING PLATE CO-ORDINATES FROM THE MODEL CO-ORDINATES OF A PLOTTING INSTRUMENT

In analytical methods of photogrammetry, plate co-ordinates are obtained from stereocomparator and monocomparator observations. These specialist instruments are too costly an investment for small organisations. The paper describes a method of obtaining plate co-ordinates from model co-ordinates and gives the results of a test experiment.     

THE ANALYTICAL ORIENTATION OF A LUNAR MODEL

An analytical relative orientation of a stereo-pair of photographs was computed in an unusual system of co-ordinates. The disparity in the widely mismatched photographs, their tilts and narrow angles subtended resulted in a rather weak solution from which sections of the lunar surface have been plotted. The results were not good but were better than expected. The main outcome of the work is a, probably unique, demonstration of the versatility of analytical photogrammetry.     

ON LINE DATA PROCESSING FOR THE PI-1A MONOCOMPARATOR USING THE BBC MICROCOMPUTER

The use of small computers for on line data processing in photogrammetry has developed from the desktop calculators of the early 1970s to the microcomputers of today. The restrictions of machine code programming, small memory and limited display have been overcome. Software has been written for the PI-1A monocomparator using the BBC microcomputer for a calibration test, relative orientation, and strip formation and adjustment in the on line mode. This low cost system is suitable for training inexperienced operators or students in analytical photogrammetry, with the sequence of observation guided by operator prompts and with error checking computations displayed. Re-observations can be made on line and acceptable observations stored for input to the strip adjustment program or subsequent block adjustment.     

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.     

应用近景摄影测量方法测制龙门桥石像等值线图

叙述了使用近景摄影测量方法绘制重庆市涪陵区蔺市龙门桥石像等值线图的全过程，包括控制测量、摄影及摄影测量处理，特别是使用了普通测量前方交会测设像片控制点的简化方法。     

基于数字摄影的钢结构变形监测系统研究

讨论了基于数字摄影的钢结构变形监测系统研究所解决的主要问题，提出了相应的解决方法，并论述了整个系统的流程。