Colour composites
Dr Nigel TroddCoventry University
Single band of data
grey levels correspond to digital numbers (DN)
Multispectral colour composite
3 gun monitor
1 band of data displayed thru’ 1 colour gun
Multiband selection
Landsat ETM+
spectral region role
1 Blue map shallow water bodies, identify forest type
2 Green discriminate vegetation & assess vigour, detect man-made objects
3 Red identify plant species & phenological status, detect man-made objects
4 Very Near IR Identify plant species, assess vigour & estimate biomass, delineate water bodies, estimate soil moisture
5 Short Wave IR delineate water bodies, estimate vegetation & soil moisture, differentiate snow from cloud cover
6 Thermal IR estimate soil moisture, analyse vegetation stress
7 Short Wave IR Identify rock type & mineralisation, estimate vegetation moisture
Panchromatic detect objects, locate boundaries
Mapping coastal waters
spectral region role
1 Blue map shallow water bodies, identify forest type
2 Green discriminate vegetation & assess vigour, detect man-made objects
3 Red identify plant species & phenological status, detect man-made objects
4 Very Near IR Identify plant species, assess vigour & estimate biomass, delineate water bodies, estimate soil moisture
5 Short Wave IR delineate water bodies, estimate vegetation & soil moisture, differentiate snow from cloud cover
6 Thermal IR estimate soil moisture, analyse vegetation stress
7 Short Wave IR Identify rock type & mineralisation, estimate vegetation moisture
Panchromatic detect objects, locate boundaries
Monitoring crops
spectral region role
1 Blue map shallow water bodies, identify forest type
2 Green discriminate vegetation & assess vigour, detect man-made objects
3 Red identify plant species & phenological status, detect man-made objects
4 Very Near IR Identify plant species, assess vigour & estimate biomass, delineate water bodies, estimate soil moisture
5 Short Wave IR delineate water bodies, estimate vegetation & soil moisture, differentiate snow from cloud cover
6 Thermal IR estimate soil moisture, analyse vegetation stress
7 Short Wave IR Identify rock type & mineralisation, estimate vegetation moisture
Panchromatic detect objects, locate boundaries
Mapping urban areas
spectral region role
1 Blue map shallow water bodies, identify forest type
2 Green discriminate vegetation & assess vigour, detect man-made objects
3 Red identify plant species & phenological status, detect man-made objects
4 Very Near IR Identify plant species, assess vigour & estimate biomass, delineate water bodies, estimate soil moisture
5 Short Wave IR delineate water bodies, estimate vegetation & soil moisture, differentiate snow from cloud cover
6 Thermal IR estimate soil moisture, analyse vegetation stress, thermal mapping
7 Short Wave IR Identify rock type & mineralisation, estimate vegetation moisture
Panchromatic detect objects, locate boundaries
Summary: 3 steps
1. Identify individual waveband(s)2. Combine (upto) 3 bands3. Allocate one band of data to one
colour gun