2. THE HISTORY OF GEOSCAN 
The Delft approach for the design and computation of networks (ref. 5) has 
become widely accepted. Tienstra (ref. 10), Baarda (ref. 2, 3 and 4) and Alberda 
(ref. 1) developed its theoretical fundament. In the sixties, scientific software 
developed at the Geodetic Computing Center of Delft University of Technology, 
confirmed the usefulness of the theory for geodetic networks. In the seventies Kok 
(ref. 7, 8 and 9) developed software system SCAN-II at Delft University of 
Technology. This system makes use of the method of variation of the parameters 
(Tienstra's standard problem Il). With SCAN-II large geodetic networks can be 
designed, adjusted, tested and analysed. The program is continuously kept up to 
date including recent theoretical investigations (ref. 9). SCAN Il was written for 
use in a scientific environment. 
In 1984 Geodelta and Geosoft Consulting initialized a project which resulted in 
GEOSCAN, a high performance adjustment system to be used on the commercial 
market and to be run on low-cost microcomputers. 
GEOSCAN should satisfy the following specifications: 
- easy to learn, easy to use; 
- implementation of the Delft approach; 
- use of the latest sparse matrix technology; 
- results easy to analyse; 
- running on PC-DOS/MS-DOS compatible microcomputers. 
3. EASY TO LEARN, EASY TO USE 
Geoscan can be used for all kinds of two-dimensional networks like: 
- polygones; 
- resections; 
- intersections; 
- triangulations; 
- closed networks. 
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