International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B3. Istanbul 2004
Line Features Min Max
100 190 100 100 1,00
081
0,64
Correctnes
000.000 EB oo o0
e > o e = e e = o in = e
I © = © >= © I
e/sjjsiselseiselse|zigiselris
EE NS DE SE
Ble {ec pie "bn [EB Zi =
E I E X
Fjordhundra | Oberpfaffenhofen | Copenhagen Trudering
E Min 8 Max
Figure 7: Correctness of line features highways, railways and
roads
Line Features Min Max
1.20 — SEE EEE
2 100 a ree Sinn bay
o ; “0897; 7
Pos
æ 060
E 040
6 0,20 +
0,00 4
Highways fesse
Railway
Highways km
Oberpfaffenhofen
Figure 8: Completeness of line features highways, railways
and roads
Fjordhundra Copenhagen Trudering
Fjordhundra is a region of agricultural structure. Therefore
no highways or railroads (as in the Copenhagen scene) exist
in this image. In case of roads the difference between the
minimum and maximum value of completeness for roads in
this area is quite big. Again at a ground pixel size of 4m in an
agricultural area it is not easy to differentiate between a land
use boundary and a small road. However the correctness
value of the found roads is satisfactory.
The completeness and correctness of linear objects like
highways and roads in the other areas is quite high and also
the variation of the interpreted results is moderate. Only one
interpreter detected the railroad in the Oberpfaffenhofen area,
while the others recognized it as road.
Area Features Min Max
120 4—— BARR m mue
1,00 +08 LA
0.30 +
0,60 +
040 4
0.20 4
0,00 +
I
Gl
Completeness
Agriculture
Agriculture TORY DEUS REDIT
Agriculture bee
Adriculture bare
ER mi
Development
Development
Development
Development
Oberpfaffenhofen Copenhagen Trudering
Figure 9: Completeness of area features development, agri-
culture, pond, forest
Fjordhundra
538
Area Features Min Max
1,20 ERAS
Correctnes
Agriculture mennnnnennnnenan*
Agriculture fot f
Agriculture jams
Development ies = Ci
Agriculture bee
Development
Development beamer
Development
Fjordhundra Oberpfaffenhofen
tiMin B Max
Figure 10: Correctness of area features development, agricul-
ture, pond, forest
Copenhagen Trudering
Figure 9 and 10 show the completeness and correctness of
the interpretation of planar features. The interpretation within
the 4 regions shows more or less a comparable quality. How-
ever for the feature “developed areas” within the Oberpfaf-
fenhofen region a remarkable difference between the mini-
mum and maximum value of correctness can be observed.
This is due to a wrong feature declaration within the SAR
image interpretation. Some areas of the airport have been de-
clared as developed in the optical image and as airfield area
in the SAR image. In the test area Fjordhundra ponds do
show a small value for completeness and correctness due to
the fact that the existing ponds are very small, and within the
optical data their colour does not allow a good recognition
and identification. The development areas in that region are
difficult to be identified because of insufficient spatial resolu-
tion.
4. CONCLUSIONS
In general all of the line and area features could be inter-
preted quite well. Difficulties could be observed with small
objects like ponds in agricultural / forest type areas and in the
recognition of railways in one of the investigated regions. Al-
though the presented results seem to be quite satisfactory, the
major drawback of this investigation is that no exact refer-
ence (topographic map or equivalent) was available for the
analysis. Therefore one has to consider uncertainties which
originate from facts like multiple meaning of some found fea-
tures in the interpretations. In this way the same linear object
may have been interpreted as a boundary or a creek or a path.
Without having a correct reference it is impossible to identify
such objects as of the correct type or not.
The analysis of the interpretation results against map data
will be part of the function of the organizer of this test. In the
next stage of this contest automatic methods of image analy-
sis and interpretation will be used.
5. ACKNOWLEDGEMENTS
We would like to express our thanks to the providers of the
test data, especially
- [ntermap Corp. and Bayr. Landesvermessungsamt
München for data from Trudering area
- DLR-IHR for the Oberpfaffenhofen data
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