SYNERGISTIC METHODS IN REMOTE SENSING DATA ANALYSIS
FOR TROPICAL COASTAL ECOSYSTEMS MONITORING
2 (^ ssp 8, Dy 4 ë
E. C. Paringit ^ "*, K. Nadaoka"
? Dept. of Mechanical and Environment
2-12-1 Ookayama, Meguro-ku, 152-8552, Tokyo, Jay
? Dept. of Geodetic Engineering, University of the Philig
KEY WORDS: Ecosystem, Inte
ABSTRACT:
Tropical coastal environments around the world have undergone rapid ¢
ts to map their extent and distribution from sp
degradation inevitable. Despite numerous attemp
signals reflected and subsequently measured by ren
have been given inadequate attention. The dynamic c
water quality and environmental stresses, both natur
these factors in understanding images obt
methods in multi-source image processing
image data covering these types of environment from
covers the Fukido river mouth area and Shiraho reef of Ishigaki Isl
from satellite-borne Ikonos, SPOT, ASTER and Landsat respectively in 2002.
ow water optics and radiative transfer
as distribution, abundance, morphology an
ational results, field surveys were conducted to gathe
face conditions, benthic habitat cover, abundance and d
iles across the reef area benthic cover were
distribution functions) modelling, shall
values with biophysical properties such
parameterizations and to validate comput
(mainly chlorophyll-a and turbidity), sea sur
synchronous with image acquisition. Spectral prot
The developed reflectance model was appli
and benthic cover estimates. Results showed relative proximity of
source image for the same area are
The accuracy of the cover and depth estimates satellite sensor
a physical basis for relating differe
1. INTRODUCTION
1.1 Background on Remote Sensing of Coastal Habitats
ent global climate anomalies and increased
Due to recurr
marine environments around
habitation in coastal zone, tropical
the world have undergone abrupt and undesirable changes.
Reckless utilization of coastal resources resulted in
deterioration of their nurtured habitats (coral reefs, seagrass
meadows and mangrove stands). In order to expediently devise
proper conservation measures and formulate sustainable
management alternatives for these coastal ecosystems, there is a
ans to obtain reliable information on the
need first to develop me
state of their health and well-being, and thereafter provide tools
to continuously monitor them.
and distribution of coastal marine
numerous and are already near
has been confined merely for
on a piecemeal and
Attempts to map the extent
habitats from space data are
pervasion. Activities, however
mapping shallow benthic coverage
intermittent mode. Regardless of restrictions cost and weather
conditions, the application of conventional remote sensing
analysis approaches to any single satellite data (c.g. IKONOS,
Landsat TM, SPOT) in current operation barely go beyond
classification accuracy above 70% (Mumby and Edwards.,
2002).
EL
* Corresponding author.
note imaging sensors to the bioph
haracteristic of the coastal shallow wate
al and anthropogenic complicate this t
ained from different sources taken at v
for assessing benthic coastal habitats such
space through the aid of theoreti
ed to the image datasets by uti
al Informatics, Tokyo Institute of Technology,
san — ecp@wv.mei.titech.ac.Jp, nadaoka@mei.titech.ac.jp
spines Diliman, Quezon City, 1101- ecp@engg.upd.edu.ph
gration, Marine, Multisensor, Multitemporal, Multispectral,
hanges which made consequent of their ecosystems
ace, the ability to relate the surface
ysical characteristics of coastal habitat targets
r areas including tidal and wave forcing,
ask. Hence there is a need to consider
arious periods. This research focuses on synergistic
as corals, seagrass, and algae by examining
ical remote sensing approaches. Our study area
and located in southern Ryukus, Japan. Images were acquired
Principles of BRDF (bidirectional reflectance
have been utilized to explain shallow water reflectance
d depth as controlling parameters. To reinforce
r in-situ data including water quality
istribution, some of which are
also used for calibrating reflectance.
lizing model inversion techniques, hence obtaining depth
image-derived reflectance to processed in-situ spectral reflectance.
also presented. The model provides
nt image datasets from different sources.
In terrestrial and global fields, immense interest has been
devoted in taking advantage of the repetitive acquisition
capability of remote sensors for discriminating landcover
features and for detecting associated changes (Coppin, 2004).
Over tropical coastal habitats, the ability to combine these
sources and make inferences from a multitude of image sources
are met with immense challenge due to a number of
considerations inherent to sensor systems and those that are
attributed to the nature of coastal environment.
1.2 The need for synergistic approach
It is hypothesized that combination of images coming from
various sources may lead to improved performance of feature
extraction and classification. This paper outlines a method for
combining imagery from different sensors that would yield a
compatible product useful for processing them in the context of
extracting resource information in coastal zones. To date, the
ability to relate the surface signals reflected and subsequently
measured by remote imaging Sensors to biophysical
argets remain elusive. À
characteristics of coastal habitat t
compounding difficulty in spectrally res
is that the dynamic nature of the coasta
including tidal and wave forcing,
environmental stresses, both from natura
olving habitat features
| shallow water areas
water quality and
| and anthropogenic
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