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ENVIRONMENT and DEVELOPMENT
Issue 3, Volume 3, March 2007
Title of the Paper: Rare Tree Species Pattern Diversity in Two Virgin Jungle Reserves in Pahang and Johor, Malaysia
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Authors: Faridah-Hanum, I & Kamaruzaman,
Hikmat, A and Latiff, A
Abstract: A study on the distribution pattern of rare tree species was carried out in Bukit Bauk Virgin Jungle Reserve (VJR), Terengganu and Gunung Pulai VJR, Johor. A single plot of 2 ha (100 m x 200 m) was established in each VJR by using purposive sampling design. The plot was further divided into contiguous 50 subplots of 20 x 20 m2. Based on the IUCN categories, six species are critically endangered and two species vulnerable in Bukit Bauk VJR. In Gunung Pulai, five species each are critically endangered and vulnerable. Both VJRs registered tree species distribution that is random and clumped in different proportions.
Keywords: Spatial distribution, Rare tree species, Virgin Jungle Reserves, Conservation, IUCN
Title of the Paper: Enhanced Model for Generating 3-D Images from
RADAR Interferometric Satellite Images
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Abstract: The advent of interferometric SAR for geophysical studies has resulted in the need for accurate
methods of two-dimensional phase unwrapping. Main approaches for phase unwrapping begin with the
measured gradient of the phase field, which is subsequently integrated to recover the unwrapped phases. They
also incorporate residue identification and cuts hence limiting the possible integration paths.
In this paper, first principal components of different quality maps are used to guide the processes of phase
unwrapping. Principal component analysis seeks directions in feature space that best represents the data in least
squares sense. It is a way of expressing data to highlight their similarities and differences.
Four types of quality maps are introduced, including Pearson coefficients, pseudo-correlation, phase derivate
variance, and maximum phase gradient. The proposed scheme depends on quality maps to guide the placement
of branch cut. It depends on the assumption that the residues are confined to a low quality regions and a quality
map guides the integration path.
The proposed model using different quality maps is verified. It was found that the branch-cut algorithm is quite
accurate but does not produce estimates in regions of highly phase noise. A new synthesis model, combining
the cuts and the outputs of principal component transformation offers greater spatial coverage with less
distortion in many instances.
Keywords: Phase Unwrapping, Radar Images, Interferometry, Quality maps, Principle Component