IX-B8, 2012
(D
Q)
1ain co-occurrence
ata set for a pixel-
-series data set for
MENTS
1ich are same with
ories were used in
P legend).
HH
BP 17 categories,
ssification classes.
h class and about
| as training data.
training data for
arsely vegetated",
ined time-domain
eaf forest" and "
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
(a) ground view (b) training area
(c)time series reflectance of = (d)time-domain
one pixel in the training co-occurrence matrix of
area the training area
Figure 4. Training data example for "evergreen needleleaf
forest".
(a) ground view (b) training area
(c) time series reflectance of (d)time-domain
one pixel in the training area co-occurrence matrix of
the training area
Figure 5. Training data example for "barren/sparsely
vegetated".
(a) "deciduous needleaf (b) " savannas"
forest"
Figure 6. Examples of obtained time-domain co-occurrence
matrix.
Classification accuracies were measured by using test samples
of 300 pixels that were sampled randomly from training area of
each individual class.
4.3 Classification Results
Because the cosine distance classifier has always produced
several percent higher mean producer's classification accuracy
than that of the Euclidean distance classifier regardless of the
time-separation delta-t, only the results when the cosine
distance is used is shown in the following. When time-domain
co-occurrence matrix is defined with reflectance, the highest
accuracy of 9596-9696 has been obtained for SR and NBAR
products when time-separation delta-t is about 3 months as
shown in Figure 7.
e SR —9— NBAR
Classification Accuracy [96]
90 T T T T T 1
1 2 3 4 5 6
Time Separation Delta-t [month]
Figure 7. Classification accuracies obtained by
time-domain co-occurrence matrix which is
defined with reflectance.
When time domain co-occurrence matrix is defined with
spectral cluster, classification accuracies are increased
according to the number of clusters as shown in Figure 8. The
highest accuracy of about 99% has been obtained for SR and
NBAR products when time-separation delta-t is about 4 months
as shown in Figure 9.
** SR (delta-t- 5 months)
77$ NBAR (delta-t- 4 months)
S 100
S
95
B
o
<
Xm
5
= 85
3
o 80 T T T T T T T T TTA
30 60 120 250 500 1000 2000 4000 8000
The Number of Clusters
Figure 8. The relationship between the number of clusters
and classification accuracies obtained by time-domain
co-occurrence matrix which is defined with spectral cluster.