Fundamentals of remote sensing

Pregunta 1 de 31

1

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

Selecciona una de las siguientes respuestas posibles:

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

Explicación

Pregunta 2 de 31

1

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

Selecciona uno de los siguientes:

VERDADERO
FALSO

Explicación

Pregunta 3 de 31

1

Label all the key points in this diagram of the temperature profile through the atmosphere. You need to name the zones defined by the temperature changes, the boundaries between them and also label the altitude axis (approximately)

Arrastra la opción correcta a cada uno de los puntos naranjas

Tropopause

Heliopause

Thermopause

Stratopause

Mesopause

Troposphere

Heliosphere

Atmosphere

Hydrosphere

Stratosphere

Mesosphere

Thermosphere

20

10

25

40

50

70

60

80

Explicación

Pregunta 4 de 31

1

Label the different regions of the electromagnetic spectrum.

Arrastra la opción correcta a cada uno de los puntos naranjas

Visible

Gamma rays

Optical

Electromagnetic

Radar

Radio

Microwave

Sonic

Seismic

Millimetre

Sub-millimetre

Thermal IR

Near Infra-Red

Ultra-violet

X-rays

Explicación

Pregunta 5 de 31

1

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

Arrastra la opción correcta a cada uno de los puntos naranjas

Molecular transitions (e.g. rotation)

High energy molecular transitions

Non-ionising electron transitions

Ionising electron transitions

Thermo nuclear transitions

Nuclear transitions

Explicación

Pregunta 6 de 31

1

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

Selecciona una o más de las siguientes respuestas posibles:

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.

Explicación

Pregunta 7 de 31

1

Which of the following best describes why a "blackbody" is black?

Selecciona una de las siguientes respuestas posibles:

It is invisible to the naked eye.
It completely absorbs all wavelengths of visible light.
It completely absorbs all wavelengths of EM radiation, including the ones we can't see.
It absorbs all wavelengths of EM radiation equally well, including the ones we can't see.

Explicación

Pregunta 8 de 31

1

Which of the following statements is NOT true?

Selecciona una de las siguientes respuestas posibles:

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.

Explicación

Pregunta 9 de 31

1

The albedo of Earth is the fraction of incident sunlight...

Selecciona una de las siguientes respuestas posibles:

absorbed at Earth’s surface, and has a value of 49%
reflected at Earth’s surface, and has a value of 5%
absorbed by Earth’s surface and atmosphere, and has a value of 31%
reflected by Earth’s surface and atmosphere, and has a value of 31%
absorbed by Earth’s surface and atmosphere, and has a value of 69%

Explicación

Pregunta 10 de 31

1

If a represents Earth’s albedo and P is the total power of sunlight incident on Earth, then the power radiated by Earth to space is approximately...

Selecciona una de las siguientes respuestas posibles:

aP
(1-a)P
1-aP
a(1-P)
a

Explicación

Pregunta 11 de 31

1

An object will appear red to the naked eye if...

Selecciona una de las siguientes respuestas posibles:

It scatters all visible wavelengths equally.
It scatters only red wavelengths and absorbs all the other visible wavelengths.
It absorbs only red wavelengths.
It transmits only red wavelengths.

Explicación

Pregunta 12 de 31

1

An object will appear white to the naked eye if...
(Note: more than one answer may be correct).

Selecciona una o más de las siguientes respuestas posibles:

it scatterers all visible wavelengths equally.
it absorbs all visible wavelengths equally.
it scatters all wavelengths equally.
it transmits all wavelengths.
it absorbs all wavelengths equally.

Explicación

Pregunta 13 de 31

1

Approximately what proportion of the mass of the Earth's atmosphere lies within the Troposphere?

Selecciona una de las siguientes respuestas posibles:

100%
95%
90%
50%
15%

Explicación

Pregunta 14 de 31

1

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

Selecciona una de las siguientes respuestas posibles:

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)

Explicación

Pregunta 15 de 31

1

Satellite observations always have to deal with ❌. One particular example is ❌ coverage (frequency of measurements) versus level of ❌. Typically, a single satellite that provides very ❌ measurements will provide a ❌ level of spatial detail.

Arrastra y suelta para completar el texto.

trade-offs

temporal

general

detail

data

frequent

infrequent

low

high

Explicación

Pregunta 16 de 31

1

In the context of atmospheric measurements, the abbreviation "ppmv" means...

Selecciona una de las siguientes respuestas posibles:

Parts per million by volume
Parts per mass of volume
Precipitation per mass volume
Particles per mass by volume

Explicación

Pregunta 17 de 31

1

Which of the following cannot (yet) be measured from satellite?

Selecciona una de las siguientes respuestas posibles:

Below ground biomass.
Above ground biomass.
mm scale ground surface displacements.
Atmospheric motion (wind).
Sea surface temperature.
Wind direction over the oceans.

Explicación

Pregunta 18 de 31

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.

Arrastra y suelta para completar el texto.

Rayleigh

Mie

Optical

Blackbody

visible

infra-red

ultraviolet

microwave

blue

green

yellow

scattered

absorbed

transmitted

red

Explicación

Pregunta 19 de 31

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).

Selecciona una o más de las siguientes respuestas posibles:

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

Explicación

Pregunta 20 de 31

1

Why are long term (decadal) measurements from satellites difficult, and how is this problem overcome?

Selecciona una de las siguientes respuestas posibles:

Satellites don't last more than a few years. The solution is to have a period of overlap in sequential missions to perform an inter-calibration between the sensors.
Satellites don't last more than a few years. The solution is to make sure sequential missions have exactly the same sensor on board.
Satellites typically don't last more than a few years because of fuel constraints. The solution is to increase the lifetime to tens of years by carrying more fuel.
The measurement instruments degrade over time. The solution is to replace the instrument in situ (i.e. in orbit).

Explicación

Pregunta 21 de 31

1

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

Selecciona una o más de las siguientes respuestas posibles:

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

Explicación

Pregunta 22 de 31

1

Rellena los espacios en blanco para completar el texto.

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).

Explicación

Pregunta 23 de 31

1

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

Selecciona una de las siguientes respuestas posibles:

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.

Explicación

Pregunta 24 de 31

1

When a blackbody warms up, it will emit radiation with ❌ total energy and with a ❌ that will go from ❌ wavelengths to ❌ wavelengths.

Arrastra y suelta para completar el texto.

more

less

equal

longer

shorter

peak

minimum

shape

Explicación

Pregunta 25 de 31

1

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

Selecciona una de las siguientes respuestas posibles:

Water vapour
Carbon dioxide
Methane
Nitrogen gas
Oxygen

Explicación

Pregunta 26 de 31

1

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

Selecciona una de las siguientes respuestas posibles:

(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

Explicación

Pregunta 27 de 31

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?

Selecciona una de las siguientes respuestas posibles:

6000km
3000km
600km
60km
6m

Explicación

Pregunta 28 de 31

1

Use Wein’s Law for this question (find this on the NLN tutorials or a source of your choice). If you heat an iron bar in a furnace, at what temperature would the rod be at to have a peak in its radiance curve in the middle of the visible range (about 550nm)?

Selecciona una de las siguientes respuestas posibles:

T= 5269 K
T= 527 K
T= 527 ˚C
T= 5269˚C

Explicación

Pregunta 29 de 31

1

Use Wein’s Law for this question (find this on the NLN tutorials or a source of your choice). If you have an iron bar at the ambient room temperature (say about 20°C) what frequency and wavelength would the maximum be? In what region of the EM spectrum is this?

Selecciona una de las siguientes respuestas posibles:

10µm or 30 THz. Thermal IR.
10µm or 10 THz. Thermal IR.
30µm or 10 THz. Thermal IR.
1µm or 100 THz. Near IR.
1µm or 30 THz. Near IR.

Explicación

Pregunta 30 de 31

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).

Arrastra y suelta para completar el texto.

352˚

8˚

90˚

270˚

188˚

172˚

Explicación

Pregunta 31 de 31

1

An EO satellite has an inclination angle of 98° and is orbiting at an altitude of 800km.
The orbital period is ❌. If the swath width is 100km, the shortest time this satellite could conceivably provide global coverage is approximately ❌. The instrument measurements ❌ cover the polar regions.

Arrastra y suelta para completar el texto.

101mins

90 mins

3 hours

120 mins

28 days

22 days

28 hours

280 days

do not

do

	Creado por Iain Woodhouse hace casi 9 años

First class quiz for Remote Sensing of Global Change, an honours module in the School of GeoSciences, Edinburgh University.

Fundamentals of remote sensing

Pregunta 1 de 31

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

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 2 de 31

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

Selecciona uno de los siguientes:

Explicación

Pregunta 3 de 31

Label all the key points in this diagram of the temperature profile through the atmosphere. You need to name the zones defined by the temperature changes, the boundaries between them and also label the altitude axis (approximately)

Arrastra la opción correcta a cada uno de los puntos naranjas

Explicación

Pregunta 4 de 31

Label the different regions of the electromagnetic spectrum.

Arrastra la opción correcta a cada uno de los puntos naranjas

Explicación

Pregunta 5 de 31

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

Arrastra la opción correcta a cada uno de los puntos naranjas

Explicación

Pregunta 6 de 31

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

Selecciona una o más de las siguientes respuestas posibles:

Explicación

Pregunta 7 de 31

Which of the following best describes why a "blackbody" is black?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 8 de 31

Which of the following statements is NOT true?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 9 de 31

The albedo of Earth is the fraction of incident sunlight...

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 10 de 31

If a represents Earth’s albedo and P is the total power of sunlight incident on Earth, then the power radiated by Earth to space is approximately...

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 11 de 31

An object will appear red to the naked eye if...

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 12 de 31

An object will appear white to the naked eye if... (Note: more than one answer may be correct).

Selecciona una o más de las siguientes respuestas posibles:

Explicación

Pregunta 13 de 31

Approximately what proportion of the mass of the Earth's atmosphere lies within the Troposphere?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 14 de 31

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

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 15 de 31

Satellite observations always have to deal with ❌. One particular example is ❌ coverage (frequency of measurements) versus level of ❌. Typically, a single satellite that provides very ❌ measurements will provide a ❌ level of spatial detail.

Arrastra y suelta para completar el texto.

Explicación

Pregunta 16 de 31

In the context of atmospheric measurements, the abbreviation "ppmv" means...

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 17 de 31

Which of the following cannot (yet) be measured from satellite?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 18 de 31

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.

Arrastra y suelta para completar el texto.

Explicación

Pregunta 19 de 31

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).

Selecciona una o más de las siguientes respuestas posibles:

Explicación

Pregunta 20 de 31

Why are long term (decadal) measurements from satellites difficult, and how is this problem overcome?

An object will appear white to the naked eye if...
(Note: more than one answer may be correct).

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).

An EO satellite has an inclination angle of 98° and is orbiting at an altitude of 800km.
The orbital period is ❌. If the swath width is 100km, the shortest time this satellite could conceivably provide global coverage is approximately ❌. The instrument measurements ❌ cover the polar regions.