# Question 7

Match the band combinations with their respective images.

## Landsat TM Band Combinations

• 3, 2, 1
• 3, 4, 5
• 4, 3, 2
• 5, 4, 3

Hints

When looking at image "C": the dark brown areas in the middle of the image are forest fire scars, the white areas at the bottom of the image are snow-covered mountain tops, the light blue line across the middle of the image is a river. There is a diagonal line of small clouds (and cloud shadows) across the top right of the image. The small black areas are lakes.

## Image Information

Mackenzie River, N.W.T.
LANDSAT TM

## Hints

### 3, 2, 1

This combination is the only one that includes band 1 with its blue sensitivity. Therefore, this combination of bands and colour assignments is the closest that we can come to making a real-colour simulation.
TM band 1 is the band most affected by atmospheric scattering, so it shows clouds, haze and smoke the best.

### 3,4,5

The red-sensitive band (#3) that has a little water penetration ability is coded as red in this band combination. The other two bands have no significant water penetration ability, so any sediment-laden water body should appear as red.

### 4,3,2

This is the simulation of the traditional of false-colour infrared film which shows healthy vegetation in shades of red./

### 5,4,3

The red-sensitive band (#3) which has a little water penetration ability is coded as blue in this band combination. The other two bands have no significant water penetration ability, so any sediment-laden water body should appear as blue.

## Landsat 5 Thematic Mapper spectral band definitions:

Band 1: 0.45-0.52 micrometres (blue-green)
Band 2: 0.52-0.60 micrometres (green)
Band 3: 0.63-0.69 micrometres (red)
Band 4: 0.76-0.90 micrometres (near infrared)
Band 5: 1.55-1.75 micrometres (near infrared)
Band 6: 10.4-12.5 micrometres (thermal infrared)
Band 7: 2.08-2.35 micrometres (shortwave infrared)