Physical Fundamentals

Question 1 of 29

1

Which of the following would NOT normally be considered as a form of remote sensing?

Select one of the following:

Sonar
Radar
Seismology
Ultrasound
Gravimetrics
None of the above. They are all forms of remote sensing.

Explanation

Question 2 of 29

1

Electromagnetic radiation can be described completely using wavelength, wave velocity, frequency and amplitude?

Select one of the following:

True
False

Explanation

Question 3 of 29

1

Label the different regions of the electromagnetic spectrum.

Drag an answer into the correct orange point.

Visible

Gamma rays

Optical

Electromagnetic

Radar

Radio

Microwave

Sonic

Seismic

Millimetre

Sub-millimetre

Thermal IR

Near Infra-Red

Ultra-violet

X-rays

Explanation

Question 4 of 29

1

Label this EM Spectrum with the typical processes that emits radiation of that approximate wavelength.

Drag an answer into the correct orange point.

Molecular transitions (e.g. rotation)

High energy molecular transitions

Non-ionising electron transitions

Ionising electron transitions

Thermo nuclear transitions

Nuclear transitions

Explanation

Question 5 of 29

1

Electromagnetic radiation can be created when... (note: there may be more than one answer)

Select one or more of the following:

an electron moves from one energy state to a lower energy state.
an molecule moves from one kinetic energy state to a lower energy state (e.g. vibration or rotation states).
an atomic nucleus changes from one energy state to a lower energy state.
an electron moves from one energy state to a higher energy state.
an molecule moves from one kinetic energy state to a higher energy state (e.g. vibration or rotation states).
an atomic nucleus changes from one energy state to a higher energy state.
None of the other answers are correct.

Explanation

Question 6 of 29

1

Which of the following statements is NOT true?

Select one of the following:

Geostationary satellites take 24 hours to orbit the Earth and therefore always remain above the same point on the ground.
Geostationary satellites are never in near-polar orbits -- they are always in equatorial orbits.
Earth observation satellites in a sun-synchronous orbit travel slightly East-to-West -- the opposite direction to the rotation of the Earth.
Some Earth observation satellites in LEO are near-equatorial, so that they only cover the tropical regions.
Sun synchronous orbits are always arranged to have a local solar time beneath the satellite at approximately 10:00-10:30 in the morning so as to minimise the cloud cover.

Explanation

Question 7 of 29

1

Which of the following in NOT an advantages of satellite measurements?

Select one of the following:

Consistent measurements globally.
Rapid large area coverage.
Near continuous measurements over many years.
Making measurements above the atmosphere.
None of the other answers (they are all advantages)

Explanation

Question 8 of 29

1

The sky appears blue because atmospheric molecules are ❌ scatterers in the ❌ part of the spectrum. Light at the ❌ end of the spectrum is therefore ❌ significantly more than at the ❌ end, where the light mostly passes through atmosphere.

Drag and drop to complete the text.

Rayleigh

Mie

Optical

Blackbody

visible

infra-red

ultraviolet

microwave

blue

green

yellow

scattered

absorbed

transmitted

red

Explanation

Question 9 of 29

1

Which of the following exhibit signs of "optical scattering" in the visible part of the spectrum?
(There may be more than one correct answer -- click all that apply).

Select one or more of the following:

Polar bear fur.
Milk.
White emulsion paint.
Clouds.
Healthy leaves.
The atmosphere.

Explanation

Question 10 of 29

1

Which of the following might a "passive" remote sensing system measure?
(Select all that apply).

Select one or more of the following:

Emitted radiation from the Earth's surface.
Emitted radiation from the atmosphere.
Solar NIR radiation scattered off the surface of the Earth.
Solar radiation scattered off the atmosphere.
Scattered microwave radiation originating from the remote sensing system itself.
Scattered NIR radiation originating from the remote sensing system itself (e.g. a laser).
Solar visible radiation scattered off the surface of the Earth.
Solar radiation after it has passed through the atmosphere.

Explanation

Question 11 of 29

1

Fill the blank spaces to complete the text.

The five different resolutions are: (based on angular resolution of the instrument), (based on pulse size for active instruments), (ability to distinguish in wavelength), (ability to distinguish different brightness levels), (ability to distinguish events in time).

Explanation

Question 12 of 29

1

Which of the following best describes the general term "resolution"?

Select one of the following:

The ability to distinguish (separate) two infinitely narrow signals in some measurement system.
The size (on the ground) of a pixel in an image.
The area (on the ground) of a pixel in an image.
The ability to distinguish (separate) two point targets on the ground.

Explanation

Question 13 of 29

1

The Earth's greenhouse effect is mostly driven by which gas?

Select one of the following:

Water vapour
Carbon dioxide
Methane
Nitrogen gas
Oxygen

Explanation

Question 14 of 29

1

1) What frequency of EM radiation corresponds to a wavelength of a) 600nm, and b) 3cm?

Select one of the following:

(a) 500 THz and (b) 10 GHz
(a) 50 THz and (b) 10 GHz
(a) 500 THz and (b) 1 GHz
(a) 500 GHz and (b) 10 GHz
(a) 500 THz and (b) 10 THz

Explanation

Question 15 of 29

1

Domestic electricity supply is at a frequency of 50Hz. What wavelength of electromagnetic radiation would you expect as a result of this oscillating electric field?

Select one of the following:

6000km
3000km
600km
60km
6m

Explanation

Question 16 of 29

1

If a satellite has an inclination angle of 98° it will pass the equator on the ascending pass with a bearing of ❌.
At its closest pass to the poles, its bearing will be ❌?
(Note, bearings are relative to North).

Drag and drop to complete the text.

352˚

8˚

90˚

270˚

188˚

172˚

Explanation

Question 17 of 29

1

Click all the following answers that you think explains why we use sinusoidal functions to describe EM radiation.

Select one or more of the following:

EM radiation has wavelike properties.
Sinusoidal functions are easy to use mathematically.
Sinusoidal functions have wavelike properties.
It works.
Sinusoidal functions can be used to explain photons.
Sine is a function button on most electronic calculators.
They work well with deci-Bels.

Explanation

Question 18 of 29

1

Drag and drop the names of the key variables in this diagram.

Drag an answer into the correct orange point.

The phase angle

The y-component of E-field

The wave amplitude

The wave vector

The direction of propagation of the wave

The wavelength

The magnetic field vector

The wave velocity

Explanation

Question 19 of 29

1

Who is this guy?

Select one of the following:

Robert Watson Watt
James Clerk Maxwell
Michael Faraday
Bernard Lovell

Explanation

Question 20 of 29

1

Correctly label this wave function.

Drag an answer into the correct orange point.

The wave function

The distance travelled

The amplitude of the wave

The sine function

The wavenumber

The wavelength

The frequency of the wave

The phase

Explanation

Question 21 of 29

1

Correctly label this equation used for describing wave properties.

Drag an answer into the correct orange point.

pi=3.14159...

Period

Wave function

The wavelength

The wavenumber

Angular velocity

Explanation

Question 22 of 29

1

Correctly label this wave equation.

Drag an answer into the correct orange point.

The wavefunction

The amplitude of the wave

The wavenumber

The time from time zero

The distance of propagation from zero

The angular velocity

The starting phase (phase at t=0)

The cosine function

The period of the wave

The wave velocity

Explanation

Question 23 of 29

1

When using imaginary numbers, we use the lower case letter "i" to represent ...

Select one of the following:

√(-1)
-√(-1)
e^(-1)
-e^(-1)

Explanation

Question 24 of 29

1

e^(-iπ)= ?

Select one of the following:

1
-1
√(-1)
0
-√(-1)

Explanation

Question 25 of 29

1

Convert the following to dB: 0.5, 2, 10, 1000, 0.1

Select one of the following:

-3.01, 3.01, 10, 30, -10
-0.30, 0.30, 1, 3, -1
-30.1, 30.1, 100, 300, -100
-6.93, 6.93, 23.1 69.1, -23.0
3.01, -3.01, -10, -30, 10

Explanation

Question 26 of 29

1

What does this graph represent?

Select one of the following:

It represents individual waves as vectors. The real and imaginary axes allow us to represent any given wave with an amplitude and a phase angle. We can add any number of wave vectors nose-to-tail to determine the resulting wave from coherently adding the waves together.
It represents individual waves as vectors. The real and imaginary axes allow us to represent any given wave with an velocity and a frequency angle. We can add any number of wave vectors nose-to-tail to determine the resulting wave from incoherently adding the waves together.
It represents the polarisation of individual waves. The real and imaginary axes are perpendicular to the direction of travel and allow us to visualise an amplitude and phase. We can add any number of polarised wave vectors nose-to-tail to determine the resulting wave from coherently adding the waves together.
It represents the polarisation of individual waves. The real and imaginary axes are perpendicular to the direction of travel. We can add any number of polarised wave vectors nose-to-tail to determine the resulting wave from incoherently adding the waves together.

Explanation

Question 27 of 29

1

(a) What kind of interference does this figure represent? (b) What is the resulting wave vector amplitude and direction?

Select one of the following:

(a) Constructive interference. (b) A wave of amplitude 2A and in the same direction as the two original waves.
(a) Constructive interference. (b) A wave of amplitude 2 and in the same direction as the two original waves.
(a) Destructive interference. (b) A wave of amplitude 4A and in the opposite direction as the two original waves.
(a) Constructive interference. (b) A wave of amplitude 2A and in the opposite direction to the two original waves.

Explanation

Question 28 of 29

1

(a) What kind of interference does this figure represent? (b) What is the resulting wave vector amplitude and direction?

Select one of the following:

(a) Destructive interference. (b) The null vector, with no amplitude or direction.
(a) Constructive interference. (b) The null vector, with no amplitude or direction.
(a) Destructive interference. (b) A vector of amplitude 2A and in the same direction as the original waves.
(a) Constructive interference. (b) A vector of amplitude 2A and in the same direction as the original waves.

Explanation

Question 29 of 29

1

What is the resulting wave vector amplitude and direction if these two waves are coherently combined?

Select one of the following:

A wave vector of length A√2 in a direction half way between the original wave vector directions.
A wave vector of length A√2 in a direction 45˚ from the real axis.
A wave vector of length 2A in a direction half way between the original wave vector directions.
A wave vector of length 2A in a direction 45˚ from the real axis.

	Created by Iain Woodhouse over 8 years ago

	Copied by Iain Woodhouse over 8 years ago

This is the first set of quiz questions to support my Introduction to Radar Remote Sensing option at the University of Edinburgh, and for people learning from my book, Introduction to Microwave Remote Sensing (eBook available on Amazon).

Physical Fundamentals

Question 1 of 29

Which of the following would NOT normally be considered as a form of remote sensing?

Select one of the following:

Explanation

Question 2 of 29

Electromagnetic radiation can be described completely using wavelength, wave velocity, frequency and amplitude?

Select one of the following:

Explanation

Question 3 of 29

Label the different regions of the electromagnetic spectrum.

Drag an answer into the correct orange point.

Explanation

Question 4 of 29

Label this EM Spectrum with the typical processes that emits radiation of that approximate wavelength.

Drag an answer into the correct orange point.

Explanation

Question 5 of 29

Electromagnetic radiation can be created when... (note: there may be more than one answer)

Select one or more of the following:

Explanation

Question 6 of 29

Which of the following statements is NOT true?

Select one of the following:

Explanation

Question 7 of 29

Which of the following in NOT an advantages of satellite measurements?

Select one of the following:

Explanation

Question 8 of 29

The sky appears blue because atmospheric molecules are ❌ scatterers in the ❌ part of the spectrum. Light at the ❌ end of the spectrum is therefore ❌ significantly more than at the ❌ end, where the light mostly passes through atmosphere.

Drag and drop to complete the text.

Explanation

Question 9 of 29

Which of the following exhibit signs of "optical scattering" in the visible part of the spectrum? (There may be more than one correct answer -- click all that apply).

Select one or more of the following:

Explanation

Question 10 of 29

Which of the following might a "passive" remote sensing system measure? (Select all that apply).

Select one or more of the following:

Explanation

Question 11 of 29

Fill the blank spaces to complete the text.

The five different resolutions are: (based on angular resolution of the instrument), (based on pulse size for active instruments), (ability to distinguish in wavelength), (ability to distinguish different brightness levels), (ability to distinguish events in time).

Explanation

Question 12 of 29

Which of the following best describes the general term "resolution"?

Select one of the following:

Explanation

Question 13 of 29

The Earth's greenhouse effect is mostly driven by which gas?

Select one of the following:

Explanation

Question 14 of 29

1) What frequency of EM radiation corresponds to a wavelength of a) 600nm, and b) 3cm?

Select one of the following:

Explanation

Question 15 of 29

Domestic electricity supply is at a frequency of 50Hz. What wavelength of electromagnetic radiation would you expect as a result of this oscillating electric field?

Select one of the following:

Explanation

Question 16 of 29

If a satellite has an inclination angle of 98° it will pass the equator on the ascending pass with a bearing of ❌. At its closest pass to the poles, its bearing will be ❌? (Note, bearings are relative to North).

Drag and drop to complete the text.

Explanation

Question 17 of 29

Click all the following answers that you think explains why we use sinusoidal functions to describe EM radiation.

Select one or more of the following:

Explanation

Question 18 of 29

Drag and drop the names of the key variables in this diagram.

Drag an answer into the correct orange point.

Explanation

Question 19 of 29

Who is this guy?

Select one of the following:

Explanation

Question 20 of 29

Correctly label this wave function.

Which of the following exhibit signs of "optical scattering" in the visible part of the spectrum?
(There may be more than one correct answer -- click all that apply).

Which of the following might a "passive" remote sensing system measure?
(Select all that apply).

If a satellite has an inclination angle of 98° it will pass the equator on the ascending pass with a bearing of ❌.
At its closest pass to the poles, its bearing will be ❌?
(Note, bearings are relative to North).