DESIGN OF A GENERAL DATA REDUCTION SYSTEM 
FOR ANALYTICAL PHOTOGRAMMETRY 
Dr. Atef A, ELASSAL 
Autometric/Raytheon 
Arlington, Virginia (USA) 
The desirability and usefulness of a general system for the adjustment of photogrammetric problems are obvious. 
The complexity of such a system can be brought within the bounds of practicality by systemizing its major components. 
The purpose of this paper is to show that a proper orientation of the mathematical analysis for the photogrammetric 
adjustment problem, combined with the utilization of advanced data processing techniques should be sufficient to bring 
into reality this highly desirable product. 
Le besoin d'un systéme général de traitement des problémes photogrammétriques est manifeste. La complexité 
d'un tel systéme ne reste pratiquement tolérable que si l'on systématise ses principaux composants. L'objet de ce rap- 
port est de montrer qu'une orientation Spécifique de l'analyse mathématique jointe à l'utilisation de procédés avancés de 
traitement des données pourrait permettre d'atteindre cet objectif hautement désirable. 
Introduction 
This paper presents a base line plan for the architecture of a data processing system e © 
capable of handling the entire range of situations that might occur in the field of close-range à 
photogrammetry, The underlying philosophy for the presented approach was previously elaborated 
upon by the author in a speech given at a recent meeting of the American Society of Photogramme- 
try [1]. In essence, a technique is to be described which makes possible the systematic 
construction of mathematical models for virtually any observed photogrammetric event, 
1. BACKGROUND 
There are two fundamental steps in the solution of any observation adjustment problem : 
- Mathematical model generation : This step involves the formation of the linear mathematical 
model which describes the observed event. 
- Least squares solution : In this step, the parameters of the generated linear model are 
statistically estimated according to the principle of least squares. 
The least squares step is totally independent of the physical situation being adjusted. 
Numerous methods have been successfully developed which both systemize and optimize the 
mechanics of this step. In one method [2] with which the author has been closely associated, 
the algorithm has developed to a point in which it could serve as an optimum system for adjusting 
any linear mathematical model. 
The situation with the mathematical model generation phase is quite different, There 
have been numerous computer programs which were developed over the span of the last decade 
to deal with a wide range of observation networks. The Scope, complexity and degree of sophisti- 
cation of these programs vary a great deal. However, they share a common characteristic of 
being directed towards a restricted configuration of rigidly defined sensor-object complexes. A 
generalized system for photogrammetric adjustment was never attempted, probably because its 
feasibility and economy seem very doubtful, 
This presentation is devoted to the development of concepts and procedures which could & © 
form as basis for a possible systematic approach to a generalized mathematical model generator. "N 
The emphasis is placed on those aspects of a system structure which point to the practicality and 
feasibility of a general least squares adjustment system in the field of photogrammetry. 
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