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Title
Remote sensing for resources development and environmental management
Author
Damen, M. C. J.

373
TABLE 2
Usefulness of Thematic Mapper Bands and Transformations
for Discerning Metal Stress in Coniferous Tree Canopies
Rank
Spain TM
Scenes
Austria TM Scenes
Spain-Austria
TM Scenes
January
August
June August
All Dates
Group I
TM4
-
BD1
ND1
PC1
TMB
ND1
R41
BD1
TM1
ND3
TMB
BD2
TM5
TM7
Group II
TM3
TMW
BD3
BD 1
TM4
PC1
TM7
R41
TMG
BD2
TM2
BD7
BD2
BD3
BD3
TM5
ND7
PC1
PC1
TMG
BD5
TM4
R43
BD7
TM5
TM5
R31
PC1
ND5
Group III
TMG
R45
TMB
TM4
BD1
R47
TMG
TMB
TM7
R23
BD7
TM5
BD3
BD7
Group IV
R2 3
R57
TM7
TM2
TMW
BD1
ND3
TM7
ND2
TMB
R43
alues" of
alues re-
ups is
orrespond-
p-ranked
ions for
TABLE 2, as
n bands and
scene
and trans-
August scene
respondence
:ase with
: Spanish
iormations
;d Spanish
:ed also
1 transfor-
/■idual scene
ire repre-
7 three of
p-ranked
md BD1) are
Lscriminat-
Eourth ranked
4. DISCUSSION AND CONCLUSIONS
The application of Thematic Mapper bands
and transformations for geobotanical pro
specting requires that a stress discrimina
tor be both robust and simple to employ. It
needs to be able to work equally well with
scene data acquired from clear as well as
hazy or cloudy (hence varying scene illumi
nation conditions) scene dates, and with low
as well as high solar elevation angles. Both
the first principal component (PC1) and the
band difference BD1 appear to meet these
criteria, with the band difference being the
simpler of the two to apply. A potential
problem inherent in utilising the first
principal component is the scene dependency
of its derived eigenvector coefficients,
which may restrict its use with data from
scenes differing significantly from the
one(s) employed in its formulation. The The
matic Mapper brightness (TMB) index, how
ever, is based on the intrinsic physical
characteristics of the scene features, there
by allowing it to be applied universally to
data sets from different regions and acqui
sition dates.
The dominant representation of Thematic
Mapper bands 5 and 7 in the higher ranking
bands and transformations of the August
Spanish scene implies a strong presence of
water stress in the pine tree canopy. This
is to be expected, as July and August are
the hottest and driest months of the year
in this part of Spain and the effects of
water stress in the trees would be most
acute at this time.
The lack of any correspondence between
the top-ranked TM bands and transformations
of the January and August Spanish scenes is
likely the consequence of the marked differ
ences in solar elevation angles (and hence
canopy shadow) between the two scene dates,
the presence of numerous cumulus clouds in
the immediate vicinity of the test site in
the August scene (resulting in varying can
opy illumination conditions), and the like
lihood of severe water stress conditions
being present in the pine tree canopy in the
August scene.
ACKNOWLEDGEMENTS: NASA Ames Research Center,
ZGF in Munich, and the European Space Angency
kindly supplied the Landsat TM CCT's of the
Spanish and Austrian test areas used in this
study.
REFERENCES
Banninger, C., 1984. Detection of Heavy Metal
Stressed Vegetation Using Landsat Digital
Data; Proc. 18th Int. Symp. Rem. Sen. Envi
ron., Paris, France, pp. 1101-1105.
Banninger, C., 1985a. Geobotanical Remote
Sensing of Heavy Metal Stressed Vegetation
Using Landsat MSS Data; Proc. Fourth The
matic Conf.: Rem. Sen. for Explor. Geology,
San Francisco, Environ. Research Inst.
Michigan, pp. 339-345.
Banninger, C., 1985b. Comparison Between
Landsat MSS and Thematic Mapper Data for
Geobotanical Prospecting in the Spanish-
Portuguese Pyrite Belt; Proc. Int. Geo
science and Rem. Sen. Symp. (IGARSS'85),
Univ. Massachusetts, Amherst, pp. 949-956.
Banninger, C., 1985c. Spectral Analysis of
a Heavy Metal Stressed Forest Canopy Using
Landsat Thematic Mapper Data; 3rd Int.
Colloquium Spectral Signatures of Objects