50 
zd 
  
  
   
   
    
  
tanbul 2004 
ing is lower 
cy (roughly 
ly the Dem 
O bias with 
1 meters. 
ig 34) : 
(North) 
1 (South) 
2 (lower) : 
  
  
St. 
  
  
  
  
  
  
  
  
  
  
  
  
  
No 
ev. match. 
8,7 | 0% 
29 17,1% 
09 11,2% 
3,4 | 0% 
5,7. | 096 
4,4 | 0% 
5,1 19,9% 
6,6 | 595 
10 | 096 
,9 | 0% 
25 areas 
Kaczynski 
declared no 
‘e complete 
hing areas, 
the filling 
tion, it can 
  
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part Bl. Istanbul 2004 
be pertinent or not depending on the use of the DEM. All our 
statistics are therefore computed from valid dots so if we 
don't have any pieces of information about those areas we 
can't get rid of them in our statistics. 
Those results are worse than the first one, on one hand 
because of the kind of landscape (this area has more 
significant relief) and on the other hand because we've got no 
declared invalid areas for some DEM. D. Poli doesn't declare 
any invalid areas but has good results in spite of this fact. P. 
Reinartz whose DEM has also a 50m sampling, which 
probably is not thin enough for this kind of relief shape. 
Even if there are some recognizing holes in K. Jacobsen and 
in R. Kaczynski DEM, we can see on profiles that the bad 
correlation has a bigger impact on DEM than only the size of 
the holes. 
Example: altimetric restitution of relief 
   
   
   
- Fig 36: Profile on P. Reinartz DEM 
This DEM is not too bad but obviously too smooth (filtering 
and 50m spacing) for the relief shape. 
   
— pee 1 | 
Fig 37: Profile on K. Jacobsen DEM 
K. Jacobsen DEM is quite good when the matching 
processing is efficient but when it's not the case, the results 
are disappointing in areas biggest than the rigorous no 
matching area. 
   
E n — vise 
Fig 38 : Profile in R. Kaczynski DEM 
The 203 m bias have been taken of the profile. This DEM has 
the same defaults than K. Jacobsen near bad correlation areas 
  
and the relief is a little bit less well drawn. 
Fig 39: Profile in D. Poli DEM 
This DEM is close to the reference, though a little bit 
smoother. 
In conclusion, in this area with a significant relief, the results 
are worse than thus were in flat area, as expected, but 
nevertheless D. Poli's obtained good results. Even with two 
kinds of modelisations, she's got results better than 7m 
without any invalid areas. 
3.5.2 Four reference DEM S 5 1/2/3/4 are available with a 
5 m sampling (Fig 40) 
  
(400 « height « 600) 
  
« heigh 
  
Sas 
  
  
S 5 3(460« height « 530) S 5 2(44 
Fig 40: Reference DEMs with 5m sampling 
  
  
All those areas are roughly flat, more particularly the third 
one. The references have a 5m sampling and a really good 
accuracy (better than 0,5m) but a small size only 5Km x 5 
Km. 
  
  
St. No 
min max |mean| Dev. [match. 
P. Reinartz 0 31 10,0 | 5,9 = 
  
K. Jacobsen] -9 34 80 | 79 | 376 
S 5 1 [R. Kaczynski] -10 26 |2044| 7,0 |1.1% 
  
  
  
  
D.Polil | -6 14 | 40 | 35 | 14% 
D.Poli2 | -7 14 | 26 | 37 | 9% 
P. Reinartz -1 40 10.4 |: 7,5 = 
  
K. Jacobsen] -15 31 sa | 82 | 3% 
S_5 2 |R. Kaczynski} -12 30 120382] 78 7 
  
  
  
  
  
D. Poli 1 -6 19 3,4 4,3 > 
D. Poli 2 -7 18 1,5 4,5 T 
P. Reinartz 0 24 7 0 4,3 = 
  
K. Jacobsen | -15 27 | 3,1 | 6,6 19,2% 
S 5 3|R. Kaczynski]. -12 28 1203,4| 57 T 
D. Poli 1 -4 11 29 128 | - 
D. Poli 2 -6 i0 10571 2971| *