- 2- 
geometric and related remote sensing problems outside of the field of photogrammetry to partici- 
pate in the discussions. The third and fourth WG meetings held in conjunction with the ASP 
  
meeting in Washington D. C. in March 1975 and in February 1976 have served this purpose. 
For this very reason it has been felt preferrable to invite the members of the WG discussions 
to report on their work as presented papers during the last two or three sessions of the ISP 
1976 congress then to channel it through a special WG report. 
While it appears to be useful that the WG should continue its existendce in view of the in- 
creasing activities, the gen eral needs and the boundless possibilities for investigation, it 
is also clear that the style of the WG should for the time being also continue. 
The WG report at he ISP Stuttgart Symposium 1974 states the general aims of the working group 
as to investigate geometric aspects of non-classical remote sensing systems based on image for- 
mation using radiated energy for the following tasks /46/ : 
1. Geometric restitution for topographic mapping 
2. Geometric correction of displays and reprexulations 
of thematic information 
Geometric registration of images for the purpose 
of spectral and temporal comparison by visual, 
electronic or digital means 
The progress for a particular imagery type can be attained in steps: 
an analytical analysis based on an appiopriate mathematical 
model applied to controlled test images 
technique for mapping of visually interpreted features in 
images 
differntial rectification of images 
automatic image correlation (at least in part for control areas) 
to derive correction functions for image registration 
The paper intends to trace and to summarite the trends of the present developments. Since a 
separate invited paper (Leberl /66/ ) will devoted to radar mapping developments the main 
emphasis of the paper will be on scanner imagery. 
2. Mathematical Models for Formation of Scanner Imageries 
The development of basic mathematical models for the treatment of scanner images and of other 
dynamic imagery had already been completed by 1972 . The Invited Papers to the Ottawa Congress 
/45, 62/ review this development for strip and panoramic photography (Case /13/, Derenyi/22/, 
Masry /70/, for scanner imagery, Derenyi /20, 21, 41/, Konecny /20, 21, 40, 41, 42, 43, 44/, 
Leberl /61/ , Taylor /82/ ), and for sidelooking radar imagery (Hockeborn /37/, Konecny/41, 
42, 44/, Leberl /57, 59, 61/, Rosenfield /76/). 
Accordingly the differential equations for scanner imagery (corresponding to Von Grubers and 
  
Hallerts parallax equations) are with © as scan angle from the vertical: 
' 
dx; 2; tg ei dk + 2: dp + dx, 
2 
' - ' 
tg 9; dz, zi (1 + tg ei ) dw + dyo 
*