The GIS application for generating various topographic maps

     The Military Topographic Institute in Dobruska is the agency 
providing topographic data to the Army of the Czech Republic.
Building of a GIS project called DMU25 started in 1994. Therefore
the institute was  equipped with four WS HP715 and software
package ArcInfo release 6.1.1. 
     The GIS DMU25 is a vector database with the same spatial 
precision as the military topographic maps 1:25000. Its extent
will be  more than 70,000 square kilometers - the whole territory
of the Czech  Republic. The DMU25 database is organized in tiles
of size of one sheet of map 1:25000. Graphic information is
stored in 20 coverages. As to the  feature attributes, feature
attribute tables contain only feature ID and  feature type code.
All remaining attributes are stored in the standard INFO 
database. Joining graphic information and attribute tables is
made by relations. The database definition, i.e., a list of all
topographic object types and their registered attribute types, is
described in „The Catalogue of  the Topographic Objects“ derived
from FACC (DIGEST).
     The structure of data combines the requirements on the
collection  of the current Czech topographic map's contents,
requirements for  maximal compatibility with the structure of
FACC, and the requirements  for generating of coverages in
ArcInfo.
     This vector database includes not only information for the
military GIS applications, but complete contents of the
topographic maps as well. One of the applications is creating of
topographic maps of scale 1:25000 and 1:50000. This solution is
built on the automated map image  generating from the DMU25
vector data. 
     Entire software system is created in the AML macro language.
It uses a user friendly menu for communication with the operator. 
     Generating of the topographic maps is divided into four
following logical steps:

1.   Selection of data from DMU25

     The goal of this block is to select information from DMU25
in  order to display it in the topographic map 1:25000 and
1:50000. In case  of the map 1:50000 it is necessary to join four
1:25000 workspaces first  and than to solve the matching of
joining object attributes. Searching for  the inconsistency
between adjacent maps (1:25000) is performed  automatically, and
then solved by the operator.

2.   Map content reduction and object displacement

     The goal of this block is reducing of geometric map content
with  respect to rules of cartographic generalization. The
solution is to select  features that should be in the map and
simplify their shapes depending on the map scale. The object
displacement of linear features is necessary  especially in the
drainage layer and in communications layer. The reason  is, that
the map symbols are considerably larger than the feature in the
real  world. Therefore it is essential to move one of the
features if they are too  close to depict both of them. The
collisions are searched for automatically  and then solved by the
operator, too.
 
3.   Symbolization

     The goal of this block is to replace the definition sets of
points by  appropriate cartographic symbols. Plotting of the map
including the frame  marginalia and annotation is performed
automatically.

4.   Map annotation

     The annotation is generated interactively and the operator
uses information from attribute tables. The operator
interactively selects the attributes of a given feature from the
database and then he places this annotation to the best location.
The annotation is stored into an annotation coverage.

     All the generated cartographic symbols and annotations are
placed  into a final map composition. The result of this process
is a postscript file that is used for generating of four films
(separated color in CMYK) in a laser image setter. The final
stage is an offset printing. 
     In near future we prepare to insert all the topographic data
into single ArcStorm database. This will not only allow to
perform global GIS tasks, but it will also facilitate creation of
maps that have map sheets and coordinate system different from
original topographic maps.