International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part Bl. Istanbul 2004
explanations for that (this might come from a transcription
error in the reading of the DEM). This DEM seems to be
quite noisy but if we look at the profile we can see as well a
little planimetric delocalization. Those problems could
probably be explained by modelisation errors (Kaczynski,
2004).
ig 31: Above: Profile in R. Kaczynski DEM (purple line)
Below: green = R. Kaczynski DEM; black = ref N_50
370< reference height<470 height exaggeration = 4
3.4.5 A. Suchkov DEM analysis shows, from statistics, that
A. Suchkov DEM is really very close to the reference. It is a
bit noisier than the reference but the sampling is not the
same. The difference image (Fig 32) is really light, that
means close to zero and the profile is also comparable to the
reference.
A RIT i RT EEE ES Mea DE. £x
Fig 32. Difference : A. Suchkov DEM — refN 50
Fig 33: Above: Profile in A. Suchkov DEM (purple line)
Below: pink = A; Suchkov DEM; black = ref N_50
370< reference height<470 height exaggeration = 4
The North area is a flat area, the reference sampling is lower
than the produced DEM but with a good accuracy (roughly
2m). There are some really good results, particularly the Dem
produced by A. Suchkov which has absolutely no bias with
the reference and a standard deviation lower than 4 meters.
3.5 Results on South areas with 25 m sampling
3.5.1 Two contiguous areas have been studied ( Fig 34) :
- S_25 1 (620 < height < 1340) 1,3 km x 10 km (North)
- S25 2 (610 « height « 1680) 8,7 km x 10 km (South)
EET Y EE m. o* — 7 ii
WET CF
ory s
- Fig34: References S 25 1 (upper) and S 25 2 (lower)
St. No
min max |mean| Dev. match.
P. Reinartz -82 58 101] 18,7 | 0%
K.Jacobsen] -51 38 12,2 | 12,9 17,1%
S_25 1 JR. Kaczynskif -22 43 [3135| 10.9 |1,2%
D. Poli 1 -12 24 6,7 | 6,4 | 0%
D. Poli 2 -9 20 $81 87 109
_P. Reinartz | -19] 58 8,5 | 24,4 | 0%
K. Jacobsen] -100 44 8,8 | 15,1 19,9%
S 25 2]R. Kaczynski]. -158 168 |210,3| 26,6 | 594
D. Poli | „26 31 3.0 7,9 |. 0%
D. Poli 2 „20 28 4,4 | 6,9 | 0%
Table 35: Accuracy and matching quality on S_25 areas
Min and max values are relative values for R. Kaczynski
results.
The "no match." Column gives the percentage of declared no
correlation areas. P. Reinartz and D. Poli DEMs are complete
DEM, that means that even if there were bad matching areas,
their DEM production proçess filled the holes, the filling
processes are always g "hetter than nothing" solution, it can
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