311
ent
ive
ely
he
tic
of
bly
as,
le.
ny
r-
represent the family units (in the case of single dwellings) upon which much
forward planning is based.
LANDSAT
(Band 4- Band 5 )
3 ]
6 v den
e. a m .
5 ^r
4.l "t .
3 PN /
P j
2 N /
Tr EN.
oi ;
0 1°2 34° 5 8g 7 979 4 Ww 12-9 1 15 1%
PARCEL SIZE M2x100
FIGURE 1: Residential parcel size (Sydney) versus difference in
Landsat bands 4 and 5.
FUTURE SATELLITES - RESOLUTION AND POTENTIAL
During the 1980's a number of higher resolution satellite systems will be
launched. Two of the most important (and nearest to launch) are the United
States Landsat D TM (Thematic Mapper) and the French SPOT satellite. Landsat
D TM will have seven spectral bands including a thermal infrared band, and a
ground resolution of 30 metres in the visible and near infrared bands. SPOT
will have four bands, two in the visible and one in the infrared, with a ground
resolution of 20 metres, and a broad visible-infrared band with a ground
resolution of 10 metres. This system will also have the potential for obtaining
stereoscopic coverage.
The pixel sizes of these two systems are compared with the typical dimensions
of residential features on the urban periphery, in Figure 2. For Sydney, at
least,this region will derive the greatest benefit from satellite monitoring.
It can be seen that the proposed resolution elements will be more comparable
with the size of features that require detection, and in addition intra-pixel
mixing will be reduced as there will be fewer surface types within a pixel (in
certain circumstances only one or two). Reduced mixing can have a number of
advantages.
(a) the reliability of prediction of surface percentages within pixels will be
considerably improved because of the increased data redundancy,
$93
E a
"di A n UND NE EI E a S EE Lia
; oy ete SE NEL