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10 Cards in this Set
- Front
- Back
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List some of the advantages of IR over
radar. |
IR is usually less susceptible to detection and interference. IR equipment is usually less complex.
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Define remote sensing.
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Remote sensing is the process of detecting or sensing infrared radiation from a target without being in physical contact with that target.
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List the similar characteristics of infrared
and light. |
IR waves have characteristics similar to light, which include reflection, refraction, absorption, and speed of transmission.
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What frequencies of the electromagnetic
spectrum are considered to be in the IR frequency range? |
The IR frequency range is from about 300 gigahertz to about 400 tetrahertz.
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Name the three IR bands of the electromagnetic
spectrum. |
1. Near infrared (NIR)
2. Intermediate infrared (IIR) 3. Far infrared (FIR) |
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List the advantages in using IR for target
detection. |
1. IR systems are passive
2. Complete jamming is difficult 3. Military targets are usually good sources of IR 4. IR systems are smaller, lighter, less complex, and less expensive 5. IR systems have a high target resolution |
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What is the blackbody concept?
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A blackbody is an object that absorbs al radiation incident on it and emits the maximum radiation for any given temperature.
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Of all the parameters in determining IR
characteristics, which one is the most important, and why? |
Temp. is the most important parameter in determining the IR characteristics of any body. As temp. of an object changes, the wavelength where peak radiation occurs shifts, and the total energy radiated varies.
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What is the primary factor that affects the
IR transmitting medium and its primary cause? |
The effect of atmospheric attenuation on transmission is a very important factor in considering the overall effectiveness of the system. The 2 primary causes are scattering by suspended particles (solids) and absorption by free molecules in the atmosphere.
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Absorption is the major cause of
attenuation in IR system design. What happens at higher altitudes? |
The absorption bands are much narrower at high altitudes because the atmosphere is thinner; therefore, there are less considerations in designing high-altitude IR systems.
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