1. Introduction 
1.1 General 
The growing demand of geographic information for urban and 
rural development, environmental monitoring, land use 
analysis and other purposes cannot any more be satisfied with 
conventional maps only. 
As a consequence, geographic data bases - either for specific or 
- preferably - for general purposes are more and more 
implemented. 
Users have defined their requirements in certain standards, 
sometimes independent from existing software. In Germany the 
Survey Authorities developed a set of different systems, where 
the *Automatisierte Liegenschaftskarte (ALK)' - ,, Automated 
Cadastral Map“ was designed as cadastral application for large 
scale mapping. 
Data capturing for the ALK-standards requires topological 
structured data and the integration of non-graphical 
information. Photogrammetry is an appropriate tool to capture 
this data, particularly for large scale mapping, both in terms of 
accuracy and economy. 
Within this paper, a procedure will be described to achieve this 
task in a consistent and economic way using Intergraph 
MicroStation 5.0 software. 
1.2 Data Structure of the German Cadastral Services 
The user requirements, a modern multi-purpose cadastre has to 
serve, can only be achieved by the use of modern technologies. 
Since 1976, some research was undertaken in Germany by the 
Surveying and Mapping Agencies of the Federal States and 
some other Surveying and Cadastral agencies to establish the 
‘Automatisierte Liegenschaftskarte (ALK) - Automated 
Cadastral Map“ [Richter (Edt.) 1993]. 
The result of these efforts is a seamless database containing 
graphical and alpha-numerical data as well as a user interface, 
a software called ALK-GIAP ('ALK-graphisch interaktiver 
Arbeitsplatz’ - graphic interactive workstation”) and a data 
exchange format called ‘Einheitliche Datenbankschnittstelle 
(EDBS)' - ,unique database exchange format“. 
The data structure is described to some extend in the 
*Objektabbildungskatalog (OBAK)' - „object description 
catalogue*, and the *Objektschlüsselkatalog (OSKA)' - ,object 
key catalogue". The layout and symbolization of the maps is 
given in the ‘Zeichenvorschrift Aut (ZV-Aut)’ - the 
specification" [OBAK 1994, OSKA 1994, ZV-AUT 1994]. 
In general, the data are organized on a layer/object type 
description, where features are divided in areas, lines and 
points with no redundancy. This leads to the multiple-theme 
approach. 
2. Logical data structure of the ALK 
The logical data structure of the geometric data is designed as 
system independent structure. The layer oriented set-up allows 
grouping of features, where for every type of feature a code 
number (OSKA-code) is assigned. This organization 
guarantees flexible handling and easy-to establish extension, if 
new features have to be accommodated. Also, the task of ‘open 
LIS’ can be achieved in this way. For this code lists have to be 
designed for every application. Groups of layers are already 
reserved for special applications. 
The basic geometric elements are point, line and area. For line, 
a set of geometric defined features is allowed: 
line straight connection between two points 
polygon chain of lines 
curve interpolated polygon (spline) 
arc part of a circle 
clotoide special, mathematically defined curve 
For specific features, an ‘Objekt’ - object is formed. This 
combines geometric elements to one feature, based on a m:n 
relationship, for the sake of easier manipulation and attaching 
additional information. 
However these are objects in the geometric sense; since the 
data model 1s not fully object-oriented. It does not support 
rules, inheritance, constrains and behavior of objects. This is 
planned as extension to the data base in the future. 
An ‘Objektname’ - , object name" is assigned to this objects, 
containing additional information (e.g. for parcels the cadastral 
division and sub-division, for houses the street name, house 
number, etc.). 
For every object - disregarding the type of geometry - an object 
coordinate is stored for identification purposes and search 
algorithms. 
Another principle of the data structure is being free of 
redundancy over the whole data set, which includes the use of 
the multi-theme features. Figure 1 shows a cadastral parcel 
765 with house number 44 , fence and a cadastral sub-division 
boundary. The parcel boundary markers and relevant points are 
numbered for reference. The lines 6-8 covers two themes - 
parcel and cadastral sub-division boundary. The thick line 
parallel servers as cartographic layout only. The lines 1-6 and 
1-4 have only partly multi-theme meaning. The part 6-7 of the 
line 1-6 is beside the parcel boundary also a fence. For 1-4 the 
double meaning healds for the part 2-3 (building and parcel). 
So multi-theme features can either be defined for complete 
geometric elements or parts of them. 
The definition of a part of a line with additional meaning is 
done by introducing the ‘unechte Punkte’ - „virtual points“, 
which have no influence on the geometry of the line, just 
defining sub-divisions (points 2,3,7 in the example). 
In order to adjust the logical data model of the ALK to the 
needs of the individual cadastral administrations, each Federal 
State has designed it’s own OSKA-code list. 
The seamless ALK database does not store a map or graphics, 
but only objects with their attributes and the spatial 
relationship between objects. The realization (e.g. display, 
plot) of the map (e.g. cartographic layout, hatching, etc.) is left 
completely to the graphics software used. 
The complex data structure of the ALK data model should be 
supported by the graphics software used in a way, that the user 
is not affected more than necessary in any stage of the work. 
As much as possible, the software has to organize the required 
data structure. 
836 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996 
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