Electro-Optical Systems

Question 1

The portion of the EM spectrum that includes radiation from UV through visible light is known as the _____ band

Answer 1

Optical

Question 2

In the visible portion of the optical band, the wavelengths are associated with ____

Answer 2

The particular colors we see

Question 3

Identify sources of radiation in the three regions normally referenced in the IR portion of the EO spectrum

Answer 3

Near IR – Solar Reflections very hot objects
MID IR – Man made emissions solar reflection
FAR IR – Natural background peak emission, man made emissions

Question 4

Describe the basic differences between reflected IR and thermal IR Radiation

Answer 4

Reflected (near) IR – used for remote sensing purposes in ways very similar to radiation in the visible light portion

Thermal Radiation – essentially radiation that is emitted from an object in the form of heat

Question 5

All objects above ____ emit IR radiation

Answer 5

0K and -273C

Question 6

What is one of the four basic IR characteristics

Answer 6

All objects above 0 k emit IR

IR behaves similarly to light

Travels at the speed of light

IR can be gathered focuses and converted to electrical signal

“All of the Above on knowledge check”

Question 7

Blackbody

Answer 7

hypothetical entity that absorbs all energy, reflects none and emits energy with perfect efficiency

Question 8

Emissivity

Answer 8

The ratio of radiant exitance of a given object and a theoretical blackbody at the same temperature

Question 9

Radiant flux

Answer 9

Rate at which photons strike a surface, measured in watts

Question 10

Radiant intensity

Answer 10

Radiant power from a point source

Question 11

Radiant exitance

Answer 11

The rate at which radiation is emitted from a unit area

Question 12

Luminous Flux

Answer 12

Radiant power, which is perceived as light by the human eye

Question 13

Identify the three forms of interaction that can take place when energy strikes or is incident upon a surface area

Answer 13

Absorption, Reflection, Transmission

Question 14

Describe the difference between emissivity and exitance

Answer 14

Emissivity an indicator of an objects ability to absorb and reradiate energy falling upon it

Exitance measure of the amount of power or energy the object is radiating

Question 15

Stefan-Blotzmann Law

Answer 15

That hotter objects emit more total energy per unit area than colder objects is part of which law

Question 16

Five factors that determine amount of attenuation for a radiant source as the IR radiation travels through the atmosphere

Answer 16

Wavelength, humidity, visibility, weather, range to the sensor

Question 17

Which of the following definitions best describes atmospheric windows

Answer 17

Portion of the EM spectrum where specific bands of EM energy can freely pass

Question 18

The objects temperature dictates characteristics of this radiation. As the temperature increases the radiant intensity _____ and shift to _______ wavelengths or _____ frequencies

Answer 18

Increases, shorter, higher