FROM SATELLITE IMAGE TO MAP - A NEW GUIDE MAP FOR FINNISH RURAL AREAS 
Kari Tuukkanen 
Helsinki University of Technology 
Institute of Geodesy and Cartography 
Otakaari 1, SF-02150 Espoo, FINLAND 
Abstract 
In the research project called "A Guide map for Finnish Rural Areas" we have developed an entirely new map 
production process as well as the map output. The goal was to develop a map for different distribution purposes, 
for emergency vehicle use as well as for general transportation. The source information was gathered as follows: 
land use information was interpreted from Landsat satellite images, height zones were generated from a DEM, 
roads and names were digitized manually on the screen, residential information was retrieved from the nationwide 
building register. In the production process, both vector and raster techniques were used. The final map output was 
designed to match the quality and type of source information. The Intergraph MGE-system (Map Publishing 
application) on Unix-workstation was utilized in the project. 
KEY WORDS: Satellite image, DEM, Map design, Cartographic theory 
1. INTRODUCTION 
In Finland, the new addressing system for rural areas obliges 
communes to update their road addresses and address-maps. 
lisalmi is a town of about 24 000 inhabitants in the central part 
of Finland. A new address-map for rural areas came into being 
in lisalmi in spring 1991. Already before that year, some ideas 
had appeared about more versatile use of the guide map. 
Emergency services, post, other distribution activities, tourism, 
and general transportation need a proper map when navigating 
in the countryside. 
In lisalmi a digital map database with Intergraph's hardware 
and software has been under construction for many years. This 
project has been quite successful and it has given some good 
practical experience to the staff. 
The Finnish National Board of Survey produces thematic map 
data from satellite images. The existence of this data and its 
usefulness for digital map production contributed to starting the 
project described in this paper. The Guide Map for Rural 
Areas’ is a totally new map type. The aim of this six-month 
project was to define the information contents of the map as 
well as the layout and production process for the new map 
type. 
The following partners were involved in the project: Geodata 
Ltd. as an expert in raster data manipulation, the town of 
lisalmi, the National Board of Survey (NBS) as the producer of 
digital data, and Helsinki University of Technology (HUT) as the 
performer of the research. A pilot project producing the guide 
map for lisalmi was included in this research project. 
This article gives an overview of the data sources used in the 
project, the production process of the map, and the design of 
the map. 
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2. DATA CAPTURE 
2.1 Land use information 
NBS produces thematic maps interpreted digitally from Landsat 
and Spot satellite images. Landsat 4 and 5 Thematic Mappers 
are the most commonly used data sources. The resolution of 
Landsat images is 30 meters. After rectification, resolution is 
improved to 25 meters. There are seven channels available for 
different wave lengths of light. 
Satellite data is manipulated by a segmentation process. 
Segmentation generates regions from pixels that have 
homogeneous densities within a certain tolerance. Segmen- 
tation is performed digitally using the Australian Disimp 
software. Mode filtering method is used in internal examination 
of the segments. 
Different channels provide different information. One channel is 
used to interpret waters. Reliability for water interpretation is 
high, 95-98%. Swamps are difficult to interpret, so a swamp 
mask taken from a Topographic Map 1:50 000 is used as 
additional information. Field is the most difficult theme to 
separate from images. Reliability for field areas is about 50%. 
A field mask of the Topographic map 1:50 000 is therefore 
used in interpretation. Percentage rates for reliability are taken 
from tests made in NBS. There are altogether 55 different 
classes in land use and forest interpretation. Classes can be 
merged with each other to achieve the ideal result for 
cartographic presentation. There are the following classes in 
the original interpretation: water, field, open area, clear felling, 
sapling stand, open swamp, pine swamp, spruce swamp, pine 
stand, spruce copse, broadleaf forest and mixed stand. Forests 
are divided into subclasses by their timber volume. 
Interpreted data is delivered in digital raster files or as 
photographic material in the required coordinate system 
(National Board of Survey, 1991). 
Data was input into the Intergraph's system as a raw raster file. 
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