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endamment de la 
- 2357 - 
METHODOLOGY OF SNOWMAPPING FROM SATELLITES 
  
by Harold HAEFNER and René MURI 
Department of Geography, University of Zurich, Switzerland 
I Introduction 
Snow in general is easy to recognize and to map on remotely sensed data. 
Therefore it was amongst the first non-meteorological features which were 
interpreted on weather satellite images shortly after the start of TIROS-1. 
On the other hand it has to be emphasized that s now belongs to the most 
difficult and heterogeneous features to be distinguished, because it occurs 
in quite a many different forms and conditions due to weather and age and 
depends upon the environment where it has been deposited and consequently 
shows a great variation in its spectral behaviour (STAENZ, 1976). 
Since the initial phase of weather satellites and in particular since the 
launch of experimental earth observation satellites snow became one 
of the major study objectives of satellite applications. Monitoring the 
snowcover from space platforms offers great advantages, may be undertaken 
for a variety of practical and scientific reasons and can be executed by 
very different interpretation methods, ranging from extremely simple to the 
most sophisticated ones. 
The first systematic study from weather satellite imagery was undertaken by 
FRITZ (1962) in Eastern Canada. Since then a vast number of studies was 
carried out, as reviewed best by BARNES & BOWLEY (1973) and in the PROCFEDINGS 
of the Workshop on "Operational Applications of Satellite Snowcover Obser- 
vations" (RANGO, Edit., 1975). 
But again a remarkable fact about snowmapping is that inspite of these obvious 
advantages, needs, and extensive activities, up to now truely operational 
applications are almost nil. Snowcover monitoring from satellites is not yet 
undertaken on a routine basis. Therefore special attention should be given 
to these facts and particular interests should be focussed on the develop- 
ment of operational snowmapping and monitoring systems. 
It is the aim of this paper to briefly review advantages, purposes and 
problems of snowcover monitoring, to survey the different existing mapping 
methods and to indicate some possibilities of methodological approaches to 
operational use.