863 - 
AIMS AND PROGRESS OF THE WORKING GROUP 
ON GEOMETRY OF REMOTE SENSING 
G. Konecny 
(Chairman, Working Group on Geometry of Remote Sensing, Commission III) 
Technical University Hannover, W. Germany 
After declassification of non-classical military sensors, such as 
the infrared scanner and the sidelooking airborne radar in the early 1960's 
remote sensing has developed as a special field, particularly through the 
symposia at the University of Michigan and the efforts of the Remote Sensing 
Committee of the American Society of Photogrammetry. 
The International Society of Photogrammetry has adopted the topic 
during the 1968 to 1972 congress period in several commissions (I, II, IV, 
V, VII). The main growing interest now comes from Commission VII. However 
remote sensing users are often confronted with geometrical problems posed 
by the different types of imagery. These problems are better approached 
with techniques of analytical photogrammetry. 
For this reason a working group was established in 1972 within 
Commission III to study the geometry of remote sensing systems. 
From the summary of sensors and their properties listed in Table 1 
one must conclude that a variety of sensors will be used for different 
purposes, resulting in different types of imageries with differing scales 
and different geometrical properties. 
The priorities for dealing with geometric tasks for remote sensing 
imagery will be established by the following requirements: 
1. Topographic Mapping , which has as its purpose to determine geometric 
positions of objects on the earth's surface and to depict them on a 
map. 
The primary sensor for this purpose is classical aerial photography. 
For low flying heights ground resolution of 1 dm is standard. Aircraft 
can however only be used to a ceiling of 20 km. For systematic flights 
above this altitude only satellites come into consideration. While 
attainable orbital heights only give ground resolutions larger than 10 
to 30 m with frame cameras, panoramic photography may increase ground 
resolution by a factor 4. It is therefore the only sensor of interest 
to mapping from satellites. 
In areas with permanent cloud cover radar permits mapping at small 
scales with a ground resolution of 10 m. The priority of developing 
methods for geometric non-classical imagery restitution will therefore 
go to the mapping radar and to special types of satellite photography.