The existing elements of the IDM 
of Denmark are presently being updated 
on the basis of various guidelines. 
A general and uniform updating policy 
must be laid down for the entire IDM 
of Denmark. 
The potential user's need for 
updating intervals for the IDM of 
Denmark should be examined more 
closely and form the basis for the 
overall updating policy. 
Some of the users, e.g. counties, 
municipalities  etc., are actually 
placed very close to the information, 
and this fact should be exploited. 
The task of the National Survey could 
here be to coordinate, manage and 
monitor this supply and to integrate 
it with its own updating. 
In order to meet needs and 
expectations, it may be necessary to 
concentrate updating of the "standard 
packages" for a number of years, and 
with that the individual elements of 
the IDM of Denmark, in the ares where 
there are users and/or subscribers. 
To cover the users' need in the best 
possible way, updating of the 
individual elements in the IDM of 
Denmark . could. be split up. into 
frequent, thematic updating 
frequencies and a somewhat slower 
total updating. 
The following updating procedures 
could be relevant for TOP-DK, for 
example: 
- public road network every year 
- buildings and boundaries every 2- 
3 years 
= total updating every 5-7 years. 
This objective could be reached by 
intensive use of external updating 
information, provided this information 
is uniform and can be checked. 
As far as the cadastral map is 
concerned, which in principle is 
updated every day, updating dates can 
be laid down for the standard 
packages. 
System integration 
When assessing the possibilities of 
coordinated production of various 
geodata products, it is paramount that 
the National Survey is seen as a whole 
from the outside as well as from 
within. 
From the external side this 
perception of the Survey as a whole 
624 
requires that uniform products and 
package solutions can be supplied 
quickly and with a high degree of 
flexibility. 
Internally it will be necessary for 
data which is used in several places or 
which .is- to. form part of a. joint 
delivery to also be suitable for "free" 
relocation and use in the different 
departments. 
As our computer systems are not 
sufficiently integrated at present, it 
will be necessary to perform an 
essential adaptation and integration of 
the individual physical systems in order 
to ensure optimum internal application 
and external access for both retrieval 
and direct access. 
Forms of supply 
Data can, of course, be supplied on 
standard data media, but other forms of 
supply can become relevant in relation 
to the application, topicality, updating 
etc. of the packages. 
For example, it should be considered 
how physical access to the IDM of 
Denmark can be established - use of fax, 
CD-ROM, new graphical terminal access 
etc. 
Data must, of course, be available 
in accordance with accepted standards 
and norms, but it is also being 
considered whether we should be capable 
of supplying packages for hardware in 
common use, both PCs and larger systems, 
and in formats for standard software in 
general use. 
It would therefore be natural for 
the National Survey to be able to supply 
the new scanned topographic maps in 
raster form on CD-ROM. A CD-ROM drive 
for a PC can be pur-chased for less than 
DKK 10,000 today, and a large number of 
dictio-naries, administrative databases 
and map databases are already available 
on CD-ROM. So technically speaking, the 
topographic raster-map can now be 
supplied on a CD-ROM for use on PCs and 
the like at an acceptable price. 
It should be pointed out that the 
costs of making the CD-ROM printing 
original are quite high. A fairly high 
number of disks will therefore be 
necessary in order to ensure a 
reasonable production price for the 
individual CD-ROM. It should also be 
pointed out that it is not possible to 
change or update data on CD-ROM. 
However, it will be bpossible to 
F2. F^ IN 0C) OO (nh OP A Lu. P^ T$ AM Inh MA 
£&uQ'ou ngo cot