SETTING UP THE DIGITISING STATION S9-D 
e of The setup of the digitising station S9-D consists of the following main 
steps: 
de), 
st- a) Map-sheet orientation: 
ial 
- A table holds the definitions of the control points to be used for 
d the transformation. The definitions are references to existing nodes, 
lar points in the database or points specially stored only in this table. 
ime. - Digitise the control points (once or several times). 
EL - Compute the transformation (Helmert, affine or projective). Results, 
n of including residuals, are presented in a form and graphically on the 
screen. Input parameters can be changed and the whole transformation 
€ can be recomputed until the user is satisfied with the result. 
rcel - The transformation parameters are set for data capture and saved for 
tour later use. 
b) Set puck menu: 
- The user can assign funtions, or sets of functions (macros), to the 
individual keys of the 16-button puck, in the same way as functions 
cor- are allocated to a function keyboard. 
ct 
ess THE PHOTOGRAMMETRIC PREPROCESSOR 
in Part of the SYSTEM 9 concept is a new analytical stereoplotter work- 
ack- station, the S9-AP. Some of its features are already described in an 
il- earlier publication (Burgermeister 1986). The photogrammetric preprocessor 
covers the following tasks: 
and 
ated a) Maintenance and management of photogrammetric data: 
y 
ion 'Photogrammetric data' means here all information necessary to establish 
models or which is involved in aerial triangulation (e.g. camera cali- 
bration parameters, orientation parameters, image coordinates, etc.) 
These data are managed by a special part of the SYSTEM 9 database 
eet called the 'photogrammetric database'. To protect the consistency of 
even this database, the user only has access to it via standard commands 
nger at the workstation. The advantage of using a database for this kind 
of data is that the well-known restrictions on file size and numbers 
34). of points are eliminated and data can easily be sorted and grouped 
ry according to different conditions. 
1- 
g b) Establishment of the photogrammetric model: 
This includes inner and outer orientation. Inner orientation covers 
also reseau cameras and the distortion correction via a grid model. 
c) Maintenance of photogrammetric model during data capture: 
The real-time program delivers not only the measured coordinates to the 
general data-capture routines, but also controls the communication with 
the special processors used for the stereo image injection (Burgermei- 
ster, 1986). 
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