SOFTWARE ENGINEERING IN PHOTOGRAMMETRIC SYSTEMS 
Tapani Sarjakoski 
The Academy of Finland 
Helsinki, Finland 
ABSTRACT 
ee DERE 
The paper reviews the role of software engineering in 
photogrammetric systems. The emphasis is on studying how to 
assure portability and reusability of different software 
components. Several tools and techniques to achieve the 
goal are investigated. Some examples of possible solutions 
in photogrammetric tasks are given. 
EEE 
ODE 
Rm 
Ee 
1. INTRODUCTION 
au 
Analytical photogrammetry in its current form and extent 
would not exist without powerful digital computers. During 
the early days of development, computers were mainly used 
for batch data processing, in the role of an efficient 
calculator. Later, computer has become to be a part of more 
complex photogrammetric systems, analytical stereoplotters 
being one of the most advanced ones. The existence of 
complex systems has also brought up the problems of complex 
computer systems: the software. The functionality of the 
system is essentially based on the properties of software. 
A natural consequence has been that the problems commonly 
known within software engineering are also relevant when 
speaking of software development for photogrammetric 
systems. 
| 
In software engineering so called software crisis was 
discovered during the 1960’s. According to (Ledbetter and 
Cox, 1985) "ambitious software projects are hard to manage, 
too expensive, of mediocre quality, and hard to schedule 
reliably. Moroften, all too often, software delivers a 
solution that does not meet the customer’s needs. After 
delivery, if not before, changing requirements mean that 
systems must be modified”. 
Solution to this crisis was tried to be found from improved 
methods for software development. 
In this presentation photogrammetric systems are analysed 
from the point of view of software engineering. The special 
characteristics of software in photogrammetric systems are 
pointed out. Then technical means and concepts suitable 
for use are introduced. Finally, Ada and some other modern 
programming languages are compared. 
= 588 "~~