EM 1110-2-2907
1 October 2003
Satellite
Sensor
Band number
Band wavelengths
Pixel Size
MSS
4)
0.5 to 0.6
79
5)
0.6 to 0.7
79
6)
0.7 to 0.8
79
7)
0.8 to 1.1
79
8)
10.4 to 12.6
240
Landsat 4-5
MSS
4)
0.5 to 0.6
82
5)
0.6 to 0.7
82
6)
0.7 to 0.8
82
7)
0.8 to 1.1
82
TM
1)
0.45 to 0.52
30
2)
0.52 to 0.60
30
3)
0.63 to 0.69
30
4)
0.76 to 0.90
30
5)
1.55 to 1.75
30
6)
10.4 to 12.5
120
7)
2.08 to 2.35
30
Landsat 7
ETM
1)
0.45 to 0.52
30
2)
0.52 to 0.60
30
3)
0.63 to 0.69
30
4)
0.76 to 0.90
30
5)
1.55 to 1.75
30
6)
10.4 to 12.5
150
7)
2.08 to 2.35
30
PAN
4)
0.50 to 0.90
15
j. Color in the Image. Computers are capable of imaging three primary colors: red,
green, and blue (RGB). This is different from the color system used by printers, which
uses magenta, cyan, yellow, and black. The color systems are unique because of differ-
ences in the nature of the application of the color. In the case of color on a computer
monitor, the monitor is black and the color is projected (called additive color) onto the
screen. Print processes require the application of color to paper. This is known as a sub-
tractive process owing to the removal of color by other pigments. For example, when
white light that contains all the visible wavelengths hits a poster with an image of a yel-
low flower, the yellow pigment will remove the blue and green and will reflect yellow.
Hence, the process is termed subtractive. The different color systems (additive vs. sub-
tractive) account for the dissimilarities in color between a computer image and the corre-
sponding printed image.
(1) Similar to the gray scale, color can also be displayed as an 8-bit image with 256
levels of brightness. Dark pixels have low values and will appear black with some color,
while bright pixels will contain high values and will contain 100% of the designated
color. In Figure 2-31, the 7 bands of a Landsat image are separated to show the varying
DNs for each band.
2-36
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