Legenstein, Dietmar 
  
  
  
  
on, | 
=, R, (2.2-8) 
dy 
Olly nn | a 
The expression derived from (2.1-7) is the second derivative of the surface and therefore describes the local 
M Xo 
curvature. 
0 n 0 ©, nm 1 
ML = MN D, =F"=F"i (2.2-9) 
Qu X. ou Xy 
F", is symmetric, because the order of the differential operators can be changed. 
  
Qux 
The differential ——"- can be calculated by inverting (2.1-5) as: 
RY 
I 
OX 
mie Rn (2.2-10) 
Q x 
I 
S. 
The differential em according to (2.2-6) is simply the Kronecker-delta. 
x. 
I 
—b=A, (2.2-11) 
  
> via quotient-rule after several steps leads to: 
N, 
The calculation of 
n 
j 
pA 
nj 
$ló"-— 
1 
(2.2-12) 
- ; k 
on, QJ HA] S, nn, 
dE. 
3 — 
  
Os, 
  
À similar calculation gives the differential 
oE re ged 
fos n[ 6s 55. (2.2-13) 
1 
ds Ann d sis sts 
J k k k 
  
  
476 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000. 
r” 
Int 
lea 
alc 
-— 4 m4