"n — M E c E m 
DIGITAL UPDATES AT THE DUTCH TOPOGRAPHIC SERVICE 
Paul van Asperen 
Research Engineer 
Topographic Service 
The Netherlands 
Commission IV, Working Group 3 
KEY WORDS: 
ABSTRACT 
Updating, Revision, Database, Vector, Digital Mapping, Change-only, Monoplotting 
The Dutch Topographic Service (TDN) is the national mapping agency of The Netherlands. It produces maps and 
databases at scales ranging from 1:10,000 to 1:500,000. The database 1:10,000, TOP10vector, is a topologically 
structured vector database. TOP10vector is based on the analogue-digital conversion of the conventional map 1:10,000. 
After the conversion, TOP10vector is updated in a digital way. This causes changes in the production method and offers 
new opportunities for data-delivery to TOP10vector-users. This article reflects the first experiences of TDN regarding 
the digital revision of TOP10vector. The production method has been successfully modified: change-only plots are, 
for example, introduced. However, data-delivery through change-only datasets to users is still an issue to be looked 
into. 
1. TOP10VECTOR: PRODUCT PHILOSOPHY 
  
  
Figure 1 Map 1:10,000 
TDN has been producing the map series 1:10,000 since 
1952. An example of this map is given in figure 1. The 
monochrome map forms also the basis for the full colour 
map 1:25,000. In 1990, it was decided to switch from 
analogue map production to digital database production. 
The actual production of the database 1:10,000 started in 
1991. This new product is called — TOP1Ovector. 
TOP10vector is a digital topographic database in vector- 
891 
format, which can be used in the scale-range 1:5,000 - 
1:25,000. Analogue maps at scales 1:10,000 and 
1:25,000 are derived from the database. 
In the early nineties, it was difficult to set up the 
specifications for a product like TOP10vector. User- 
requirements could not be formulated because experienced 
digital data-users did not exist. Therefore, three main 
starting points were formulated: 
- TOPiOvector should be kept simple in order to be 
useful for as many users as possible 
- TOPl1Ovector should be compatible with as many hard- 
and software-systems as possible, especially GIS 
- the maps 1:10,000 and 1:25,000 should be produced 
directly from TOP10vector. 
As a result, TOP10vector contains all map features that 
appear on the maps 1:10,000 and 1:25,000. To comply 
with the second starting point, it was decided to structure 
the vector data in a topological way, which facilitates the 
use of the data in GIS. It was also decided to produce 
TOPlOvector in a CAD-environment, in this case 
Microstation-software running on  Intergraph- 
workstations, because the geometrical objects and their 
attributes can be produced efficiently in this environment. 
No relational attribute database would be used. This 
decision needs more clarification, because some other 
national mapping agencies have decided to produce their 
databases in a GIS-environment. 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996