Heft 5/1981

Schriftenreihe
des Instituts für Geodäsie



Heft 5/1981

TORLEGÅRD, Kennert

Accuracy Improvement in Close Range Photogrammetry

(8) 68 S.

ISSN:  0173-1009

Table of Contents

Preface

Abstract


 

 

Contents

Preface
 
Acknowledgements
 
Abstract 1
 
1  Introduction 2
 
2  Mathematical Model  
    2.1  The bundle approach 3
    2.2  Convergence criteria for iterations 6
    2.3  Lens distortion and additional parameters 8
    2.4  Accuracy of control points 9
    2.5  Interpretation of results 9
 
3  Measures of Precision, Fidelity and Reliability  
    3.1  Terminology 10
    3.2  Definitions 11
    3.3  Experimental design 13
 
4  Blunders in Photogrammetric Data  
    4.1  Blunders in adjustment 14
    4.2  A suggested test statistic  Fmax  19
    4.3  The  Qvv -matrix 19
    4.4  Distribution function of  Fmax  20
    4.5  Blunder localization 24
 
5  Stochastic Properties of Image Coordinates  
    5.1  True errors and residuals 27
    5.2  Empirical studies 32
    5.3  Cartesian or spherical and cylindrical coordinates 34
 
6  The Multi-Concept in Close Range Photogrammetry  
    6.1  High accuracy procedures 35
    6.2  Multi-readings 37
    6.3  Multi-fiducials 43
    6.4  Multi-targets 47
    6.5  Multi-frames 49
    6.6  Multi-stations 53
    6.7  Multi-control 55
    6.8  Multi-purpose programm 56
 
7  Conclusions 59
 
References 61
Appendix 66
 

 
Preface

The following study is part of a report from a six months' research stay as Visiting Professor for Engineering Photogrammetry at the Hochschule der Bundeswehr München. This study may be seen as a summary of the state of art in highly accurate close range photogrammetry with emphasis on detection, localization and elimination of blunders in observations. Several hitherto unsolved problems have been defined, and some new research plans have been outlined. It is my hope that the survey of available methods to achieve high accuracies in close range photogrammetry given in this report will be of value for engineers and surveyors using close range photogrammetry as a measuring tool, and that it will be a stimulance for scientists and researchers to set out new goals for the development of this mensuration technique.
 



Abstract

The state of art in highly accurate analytical photogrammetry is briefly overviewed. The concept of accuracy is described as precision, model fidelity, and reliability, where precision is related to random errors and their propagation, model fidelity to systematic discrepancies between reality and mathematical model, and reliability to detection, localization and elimination of blunders. The effect of blunders in least squares adjustments is outlined, and a procedure in order to localize blunders after adjustment is suggested. The possibility to localize and eliminate blunders in all phases of the photogrammetric process is discussed in detail, particularly for close-range applications. The principle of redundancy to achieve reliability is demonstrated, leading to the multi-concept in photogrammetry. It can be applied to all steps: coordinate readings, fiducial marks, targets, frames (new method of overlapping), stations, control points, object geometry, computer program options. Simultaneous adjustment of observations, of image coordinates, observations of exterior orientation elements, geometric conditions in object space, and approximations for the unknowns are reviewed. Several hitherto unsolved problems and open questions have been stated.
 


 
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