The systematic deformations are usually accommodated by 
adding a function f(x,y) of the image coordinate to the 
projective relations. 
xp" = Px" (Np,Ep,Hp) + Ex? (Xp, vp(9) 
yp" = Py" (Np,Eo,Hp) + Fy“ (Xp, vp) (1) 
For block adjustment, F is approximated by polynomials in 
x and y with a limited number of unknown coefficients. 
This approach, although valid, poses a large number of 
practical problems, such as: which polynomial to choose, 
how to separate systematic deformations from blunders, 
which ground control distribution is necessary for 
avoiding under-determination etc. (see also Kubik, 1988). 
We therefore propose here a novel and elegant approach to 
this problem, which also is valid for other projections 
such as existing in remote sensing, tomography and other 
fields. 
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