CONS 127-Final Exam UPDATED
QUESTIONS AND CORRECT ANSWERS
Passive remote sensing - CORRECT ANSWER Passive remote sensing measures energy that is
naturally emittedo Typically from the sun (photos)
O And reflected off of targets/surfaces Remote Sensing Illustration (Source: Wikimedia Commons)
Measrued by lansat,worldiview
Active rmeote sensing - CORRECT ANSWER send out electromagentic signals (photos)
-trvales from isnturment and bocuens off surface and back to sensor and measure
-no sun energy
- data to groudn station
Actove remote sensing advnatages - CORRECT ANSWER -weather indepdent (for radar) not
affected by clouds
Sunligth idnddent: nor elaicne one enrgy on sun, survey anytiem of day even at night
-control type of energy emitted
Can penetrate vegetation, soil,ice and snow
- Information on surface layers andstructure, 3d strcutures, only radar
Microwaves go through - CORRECT ANSWER clouds
Disadvnatages - CORRECT ANSWER Limited spectral information
-soemtimes none
,-only type of radation, not multiple emasuremtns across eelgnmogantiv spectrum
• Complicated analysis
Ranging compoenent, 3d is way more diffuclut
• Costly
Why would active remote sensing have limited spectral information? - CORRECT
ANSWER hard to tell differcne from sone, fi sjut oen evrye asy to tell
Radar - CORRECT ANSWER radio Detection And Ranging
Adar works with different wavelengths in the microwave part of the spectrum, by:
1. Transmitting a microwave (or radio) signal towards a scene
2. Receiving the portion of transmitted energy backscattered from the scene
3. Observing the strength (detection), orientation and time delay (ranging) of the returnsignals, hititng
off gorudn anc bakc to onsutrmen jow long
Can calcualtue how far that mcirowave boucned off
Why use radar - CORRECT ANSWER active microwave energy penetrates clouds and serves
as an all-weather remote sensing system
• Coverage can be obtained at user-specified times, even at night
Three factors govern the response of the backscatter - CORRECT ANSWER surface roughness
Diffuse reflectio : forest
,Specualr reflection: ncie relection abck flast ice (more backscatetr)
Highets with corenr reflection
Dielectric, properties moisture content (increeas ebackscatetr because mositure is good conducter)
Chemical makeup infeucne how eelctriclaly codncutive proeprty is, hgigher dieltic means more
reflected energy
Backscatetr - CORRECT ANSWER reflecte microwave enrgy iff of surface
Bands - CORRECT ANSWER X, C,L, P in that order smalelst to largert and least groudn
concentration in order
Longer the wavelength, proption to abiltiy to peternate groudn
General rule - CORRECT ANSWER choose the wavelength that approximates the objects
ofinterest
Radarsat 1 and 2 - CORRECT ANSWER -canada made
First operational civilian RADAR satellite launched innovember 1995• RADARSAT 2 Launched In
Dec 2007• C-band
An see through clouds and very good at detecting sea iceand snow• Covers polar regions daily
, • Temperate zones every 3 days; Tropical zones every 5 day
Water and ice have contarst ins urface roughness
Radar cosntelltion - CORRECT ANSWER • 3 Identical smaller satellites, hugher spcail
reosltuion
Artiffically increase temporal resolution of satltties, withotu comrposimign reosltuion
Why is RADAR particularly suitable for a country like Canada?• Hint: - CORRECT
ANSWER ice and snow, coastline, rafdar coudl for diffetnting
-lots of clouds
- not a lot of sun in winter in northern part of canada, experiecn 24 horus of sunlught
3 uses of RADAR - CORRECT ANSWER mapping Antarctica, radarsat 1 in 1997, so logn
because passive isntuements and clouds
First complete map of the speed and direction of ice flowon Antarctica derived from RADARSAT-2
with rnaign measuremtn
What age layers of use are, ash from volacnos shwo up in core to tell age
Oil spills - CORRECT ANSWER oilspills need to respond to right away, sees through clouds or
its dark
Surfzace roughess: l floats on water, suppressingoceanic capillary waves, and creatinga surface that is
smoother than thesurrounding wate
QUESTIONS AND CORRECT ANSWERS
Passive remote sensing - CORRECT ANSWER Passive remote sensing measures energy that is
naturally emittedo Typically from the sun (photos)
O And reflected off of targets/surfaces Remote Sensing Illustration (Source: Wikimedia Commons)
Measrued by lansat,worldiview
Active rmeote sensing - CORRECT ANSWER send out electromagentic signals (photos)
-trvales from isnturment and bocuens off surface and back to sensor and measure
-no sun energy
- data to groudn station
Actove remote sensing advnatages - CORRECT ANSWER -weather indepdent (for radar) not
affected by clouds
Sunligth idnddent: nor elaicne one enrgy on sun, survey anytiem of day even at night
-control type of energy emitted
Can penetrate vegetation, soil,ice and snow
- Information on surface layers andstructure, 3d strcutures, only radar
Microwaves go through - CORRECT ANSWER clouds
Disadvnatages - CORRECT ANSWER Limited spectral information
-soemtimes none
,-only type of radation, not multiple emasuremtns across eelgnmogantiv spectrum
• Complicated analysis
Ranging compoenent, 3d is way more diffuclut
• Costly
Why would active remote sensing have limited spectral information? - CORRECT
ANSWER hard to tell differcne from sone, fi sjut oen evrye asy to tell
Radar - CORRECT ANSWER radio Detection And Ranging
Adar works with different wavelengths in the microwave part of the spectrum, by:
1. Transmitting a microwave (or radio) signal towards a scene
2. Receiving the portion of transmitted energy backscattered from the scene
3. Observing the strength (detection), orientation and time delay (ranging) of the returnsignals, hititng
off gorudn anc bakc to onsutrmen jow long
Can calcualtue how far that mcirowave boucned off
Why use radar - CORRECT ANSWER active microwave energy penetrates clouds and serves
as an all-weather remote sensing system
• Coverage can be obtained at user-specified times, even at night
Three factors govern the response of the backscatter - CORRECT ANSWER surface roughness
Diffuse reflectio : forest
,Specualr reflection: ncie relection abck flast ice (more backscatetr)
Highets with corenr reflection
Dielectric, properties moisture content (increeas ebackscatetr because mositure is good conducter)
Chemical makeup infeucne how eelctriclaly codncutive proeprty is, hgigher dieltic means more
reflected energy
Backscatetr - CORRECT ANSWER reflecte microwave enrgy iff of surface
Bands - CORRECT ANSWER X, C,L, P in that order smalelst to largert and least groudn
concentration in order
Longer the wavelength, proption to abiltiy to peternate groudn
General rule - CORRECT ANSWER choose the wavelength that approximates the objects
ofinterest
Radarsat 1 and 2 - CORRECT ANSWER -canada made
First operational civilian RADAR satellite launched innovember 1995• RADARSAT 2 Launched In
Dec 2007• C-band
An see through clouds and very good at detecting sea iceand snow• Covers polar regions daily
, • Temperate zones every 3 days; Tropical zones every 5 day
Water and ice have contarst ins urface roughness
Radar cosntelltion - CORRECT ANSWER • 3 Identical smaller satellites, hugher spcail
reosltuion
Artiffically increase temporal resolution of satltties, withotu comrposimign reosltuion
Why is RADAR particularly suitable for a country like Canada?• Hint: - CORRECT
ANSWER ice and snow, coastline, rafdar coudl for diffetnting
-lots of clouds
- not a lot of sun in winter in northern part of canada, experiecn 24 horus of sunlught
3 uses of RADAR - CORRECT ANSWER mapping Antarctica, radarsat 1 in 1997, so logn
because passive isntuements and clouds
First complete map of the speed and direction of ice flowon Antarctica derived from RADARSAT-2
with rnaign measuremtn
What age layers of use are, ash from volacnos shwo up in core to tell age
Oil spills - CORRECT ANSWER oilspills need to respond to right away, sees through clouds or
its dark
Surfzace roughess: l floats on water, suppressingoceanic capillary waves, and creatinga surface that is
smoother than thesurrounding wate
