The characteristics of PALSAR γ0
HH and γ0
HV for natural forests and
deforested areas are shown in Fig. 5. Table 3 shows the average and
standard deviation of γ0 in natural forests and deforested areas. There
were no clear differences between dry forests (sites D1–D3) and wet
forests (sites W1–W3). The average γ0
HH did not show clear changes
between deforested areas and natural forests, but the average γ0
HV of
deforested areas was systematically lower by 1–4 dB than that of natural
forests. Spatial patterns in the γ0 differences are shown in Fig. 6. In
the image of HV polarization, there are many geometric patterns in
which γ0
HV shows an obvious decrease,whichmay be due mainly to deforestation.
However, the image of γ0
HH differences shows only a few
clear geometric patterns. According to these results, in the study area,
the time series difference of γ0
HV can be a simple and clear indicator
of deforestation with the use of thresholding, hence only γ0
HV is used
in the following analysis.
The characteristics of PALSAR γ0HH and γ0HV for natural forests anddeforested areas are shown in Fig. 5. Table 3 shows the average andstandard deviation of γ0 in natural forests and deforested areas. Therewere no clear differences between dry forests (sites D1–D3) and wetforests (sites W1–W3). The average γ0HH did not show clear changesbetween deforested areas and natural forests, but the average γ0HV ofdeforested areas was systematically lower by 1–4 dB than that of naturalforests. Spatial patterns in the γ0 differences are shown in Fig. 6. Inthe image of HV polarization, there are many geometric patterns inwhich γ0HV shows an obvious decrease,whichmay be due mainly to deforestation.However, the image of γ0HH differences shows only a fewclear geometric patterns. According to these results, in the study area,the time series difference of γ0HV can be a simple and clear indicatorof deforestation with the use of thresholding, hence only γ0HV is usedin the following analysis.
การแปล กรุณารอสักครู่..
