v
es
on
he
in
Data
mit
of the
erman
nland-
of this
forest
est is
south,
forest
small
of the
Figure.1: Landscape unit in the south Palatine Forest
Landinformation System
For the spatial and spectral analyse of the remotely
sensed data and for verification of classified images it
was necessary to build up a landinformation system with
reference data for the forest and non-forest areas.
Based on the nomenclature table , which was developed
together with the nature park administration and the
technical project partners for the classification process a
landinformation system was build up using forest
management data from 1996 for forest areas and
topographic and vegetation data.
In addition main thematic information layers listed below
were integrated in the landinformation system .:
- geological map 1:200.000
- map of climate 1:200.000
- digital elevation model (DGM)
- topographic maps 1:25.000
- maps of biotops 1:25.000
- forest map 1:25.000
- forest soil maps 1:10.000
- grassland maps 1:25.000
- landuse maps 1:25.000
- CORINE-landcover classification
- administration units
Based on this geo data the description of the
investigation area and the selection of training data sets
were carried out.
Satellite Data
For the research work two SPOT XS data sets from June
1992 and April 1995were ordered. The data sets are
characterised by a side looking data take. According to
the view angle of -16° it was necessary to run an
orthorectification on the data sets.
In addition one LANDSAT TM data set from July 1994
and one panchromatic IRS-1C data set from April 1997
was provided.
Pre-Processing
The pre-processing the above listed data set were
analysed regarding to radiometric errors. The TM data set
( processed in Fucino, Italy) was characterised by un-
systematically distributed double lines with the same
radiometric values and a forward/reverse scan banding
( Crippen, 1989). The correction of the unsystematically
double lines was impossible with available algorithms and
in an appropriate time. The use of the TM-Band-
Correction algorithm based of the work of (Crippen, 1989)
was not successful. Some parts of the dark banding lines
were still overcorrected while other parts were sufficiently
corrected.
The banding of the IRS-1C PAN image was in
comparison to the 1996 data strongly reduced but still
visible in the data set. Based on the processing steps
after data reception the IRS-1C data set is coarsely
georectified to the German Transverse Mercator
coordinate system, which rotates the banding lines in the
IRS-1C image.
Georectification
The georectification of the data sets was carried out using
a map-to-image rectification for the SPOT-XS data set
from 1995. The other images were rectified by a image-
to-image rectification.
The map-to-image rectification with the spatially high
resolution image was not possible according to the late
delivery of the data set in December 1997.
Based on 32 control points the satellite data sets were
rectified. The errors of rectification were calculated with
0.3 to 0.5 pixels for the SPOT- and LANDSAT data sets
and with 0.7 pixels for the IRS-1C PAN data set.
Topographic Normalisation
Topographic Normalisation on the cosine basis was
applied. Due to the overcorrection of shadow areas this
was rejected and substituted by illumination masks.
For the classification 4 data sets from LANDSAT TM (July
1994), SPOT XS (June 1992, April 1995) and IRS-1C
PAN (April 1997) were available.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998 371