Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GIS > Exam 3 > Flashcards

Exam 3 Flashcards

1
Q

Define Incident Energy

A

the total energy per wavelength that is reflected from some surface.
I= Transmission + Absorption + Reflection
I=T+A+R

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define Spectral Reflectance

A

% of total energy for each wavelength that is reflected by the target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does remote sensing record?

A

Brightness values

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 3 processes of light?

A

Absorption
Scattering
Transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define Absorption

A

When light is held by something. Ozone and molecular oxygen absorb different wavelengths of the UV range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define Rayleigh Scattering. Give an example.

A

Atmospheric particles are much smaller than the incoming wavelengths
ex) why sky is blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define Mie scattering, give an example

A

Atmospheric particles are about the same size as the incoming wavelengths.
Ex) haze

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define Non-selective Scattering, give an example

A

Atmospheric particles are much larger than wavelengths. Acts on all wavelengths equally.
Ex) water droplets reflecting all colors = white clouds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define Transmission

A

When light passes through a target. Comes through atmospheric windows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What wavelengths are atmospheric windows are open, partially open, and closed to?

A

Open: radio waves, visible light
Partial: IR and UV
Closed: x-rays and gamma rays

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define Spatial Resolution

A

Pixel size. Smallest level of detail that can be discerned from the ground.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is Pan-sharpening?

A

Fuse a color band (lower resolution) over a panchromatic band (higher resolution). Not perfect but can sharpen resolution of colored image.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define Spectral Resolution

A

Number of bands and their widths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the width of a band determine?

Fatter band = ? resolution

A

How small of features can be discerned from the ground.

Fatter bands = worse resolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define Spectral Signature

A

the % of energy being reflected back from an object. Unique. Can be used to isolate what you are looking for.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the two color composites and what do they require?

A

True color and false color deposits (the latter used for juxtaposition)
Require RBG channels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are spectral indices? Give an example

A

They look at the relationship between different spectral bands (beyond what you can see from a RBG combo) NDVI is an example

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Define Orbit

A

A regular, repeating path that one object in space takes around another one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Define Satellite

A

An object in orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Define Geostationary Orbit. What is this good for?

A

Always looks at the same spot.
Exactly matches the speed over the rotation of the Earth.
Over equator
Use: weather, tv, communication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Define Near-Polar Orbit. What is it good for?

A

Always passes over the same patch of ground at the same time of day.
Use: looking at change through time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Define swath width

A

The ground area a satellite images as it passes over. Same thing as an IFOV for an aerial image.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the two scanning types?

A

Across-track and along-track scanning.

One is not better or worse than the other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does Radiometric resolution determine?

Narrower slices = ? bit depth= ? resolution

A

Determines how fine a level of energy you can determine with. Narrower slices (greater bit depth) has better resolution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Define Band

A

Range of wavelengths that may be measured by a remote sensing device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are brightness values?

A

the energy measured at a single pixel according to a predetermined scale (what RS is measuring)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What bands can be captured by RS? In order from shortest to longest wavelength?

A

Visible Light (Blue, Green, Red), Near Infared (NIR), Shortwave Infared (SWIR), Thermal infared (TIR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the 4 types of resolution? What do they measure?

A

Spatial Resolution- what level of detail
Spectral Resolution- what colors or bands
Temporal Resolution- revisit time
Radiometric Resolution- color depth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the temporal resolution of the current Landsat?

A

16 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Define Off-nadir viewing

A

Capability of a satellite to observe areas other than the ground directly below it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Blue Band: range and uses

A

0.4-0.5 um
Deep water imaging
Smoke plumes, atm haze, clouds
Clouds, snow, rock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Green Band: range and uses

A

05.-0.6 um
Plant vigor and vegetation
Algal and cyanobacterial blooms
Urban recreation (parks)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Red Band: range and uses

A

0.6-0.7 um
Soil types and geological features
Chlorophyll absoption (NDVI)
Built vs natural environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

IR (infared): range and subsets

A

0.7-100 um

NIR, SWIR, TIR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

NIR (near infared): range and uses

A 
0.7-1.3 um
Biomass content
Archaeological sites
NDVI
Vegetation
Land/water boundaries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

SWIR (shortwave infared): range and uses

A 
1.3-3.0 um
Moisture content
Cloud/smoke penetration
Mineral exploration
Water properties (turbidity)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

TIR (thermal infared): range and uses

A 
3-14 um
Volcano activity
Urban heat
Weather prediction
Wildfire tracking
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Visible Light spectrum range

A

0.4-0.7 um

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

UV range

A

0.01-0.4 um

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Define NDVI

What is its range?

A

Normalized difference Vegetation Index.

NDVI= (NIR-Red)/(NIR+Red)

Ranges from -1 to +1 (-1 means nothing is growing and +1 means healthy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What was Sputnik?

Year, country, what did it do?

A

1957, USSR, first artificial satellite.

Beeped for 3 weeks then died. Officially started the space race.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What was the International Geophysical Year?

Legacy?

A

1957-1958
67 countries developing technology for space and elsewhere.
Legacy: atm studies, midocean ridges, radiation belts, Antarctic Treaty

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What was the fallout from Sputnik 1? What did it lead to?

A

Public panic, not government

Directly led to NASA, lunar program, DARPA, and a renewed interest in math and science in education.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What was Explorer 1?

Year, country, what did it do?

A

1958, USA, our first sat.
Returned data for 4 months.
Smaller, lighter, and longer lasting than sputnik

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What was the Corona Program?

Years, purpose

A

1952-1972
Took BW images of different places on Earth (Russian reconnaissance 1960)
Ejected film canisters, salt plug.
Many failures at first.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What was Skylab?

year, for what, for whom

A

1973
Largest manned space stations
24 weeks, hundreds of missions (science nerds)

47
Q

What is Kennen KH-II?

year, purpose, for whom

A 
1976-present?
Defense purposes
First electronic imaging sat that could send real-time.
KH= keyhole (spying)
No one knows what they look like.
48
Q

Landsat

What is it, years, for whom

A

Landsat is the longest running continuously operative remote sensing platform.

1972-present. Landsat 9 to launch in 2020
All data now freely available.

49
Q

LandSat 7

What major issue does it have?

A

2003: scan-line corrector (SLC) on satellite failed.
Ended up with huge black bands in place of up to 25% of image.
Still usable, just needs correction

50
Q

LandSat Ground Station Network
Where?
Problems?

A

EROS center in North Dakota to be processed.
Transmitting in real time w/in zone or records until it gets into a zone.
Hacked once.

51
Q

LandSat Catalog.

What is it? how do you use it?

A

World wide Reference system using paths and rows to find LandSat scene (RI fits into one)

52
Q

Define EROS

A

Earth Resources Observation Science Center. Serves as a downlink station for satellite imagery.

53
Q

What is the Copernicus Program?

A

EU’s Earth Observation Program.

Sentinel 1A/B-6 (current)

54
Q

Define Satellite constellation.

What does this do?

A

2 or more satellites working in tandem in same orbital plane with similar or same sensor.
Gives you near complete coverage and better revisit time.

55
Q

Sentinel 1A/B

What does it do?

A

Sea ice and land movement.

Can make a banthometric map.

56
Q

Sentinel 2A/B

What does it do?

A

Similar applications to LandSat
multispectral, revisit time 5 days
Better resolution than LandSat 8

57
Q

Sentinel 3A/B

What does it do?

A

Marine oriented. Land and ocean color.

Revisit time 1-2 days.

58
Q

Sentinel 4, 5, 6

What do they do?

A

Yet to be released.
Sentinel 4: air quality
Sentinel 5: atmosphere
Sentinel 6: more advanced Radar

59
Q

What are the two biggest government satellite programs?

A

LandSat (USA), Sentinel (EU)

60
Q

What was the Land Remote Sensing Policy Act?

A
  1. Allowed US companies to operate imaging satellites in space.
61
Q

IKONOS-1

Years, what did it do?

A

1999-2015
1st commercial high resolution sensor
Revisit time 3 days (much better than LandSat 7)

62
Q

SPOT

Years, what did it do?

A

Originally French gov backed financially
1986, 2014
Similar to others in function.

63
Q

World View-3

Years, what was unique

A

launched 2014.
1ft resolution, 1 day revisit.
Can point mirror to task the satellite.

64
Q

What are the trends in satellite technology?

A 
Better resolutions (temporal, spectral, spatial, and radiometric)
Spatial resolution is getting finer but swath width also becomes smaller.
65
Q

CubeSat

Years, what is unique

A

Launched 2003
small block units, 1-6 units
Off shelf components, cheap, reduces research costs

66
Q

SkySat and PlanetScope

unique properties

A

SkySat: cube concept but fridge size. Can get video.

Planet Scope: doves and flocks. Huge coverage.

67
Q

CZCS

Define, years, purpose

A

Coastal Zone Color Scanner
1978-1986.
First ocean color imagery.

68
Q

Sea-WIFS

Years, unique properties, purpose

A

1997-2010
Global bio data.
Changed sensor angle as it passed over equator to avoid glint and sensor blowout.

69
Q

NASA’s Earth Observing System

Program name, years, type of satellites, issues

A

MODIS program.
Terra and aqua sats, 1999 and 2002, overdue.
Gaps between swaths but 36 bands

70
Q

VIIRS

Years, purpose

A

SUOMi NPP partnership
to replace MODIS
No more gaps with better coverage.
2011.

71
Q

What are some things you need to specify to someone who resells imagery?

A

Which satellite, what resolution, what temporal component, area of interest, how many clouds, etc

72
Q

What does the cost of satellite imagery depend on?

A

Minimum order size, which satellite, if it’s already in archive, etc

73
Q

How do you manipulate the temporal component to get a better picture?

A

averaging days together, or even months.

Months over years creates a composite with less details but a much cleaner picture.

74
Q

What data level do most typically ask for

A

Level 3

75
Q

Define SDB

Who uses it? What are the limitations?

A

Satellite Derived Bathymetry
Used by NOAA and others to remap nautical maps, especially when coupled with LandSat data
Limited by turbidity

76
Q

What are some examples of LandSat 8 uses. Think TIR

A

California wildfires, Yellowstone new hotspot formation

77
Q

How does active remote sensing use energy?

A

Sensor generates its own electromagnetic energy directed at the target

78
Q

What is received by an active remote sensor?

A

backscattering

79
Q

What are some advantages of active remote sensing?

4

A

Active day or night in all weather.
Can determine if something is moving.
Can measure the distance of an object.
Provides exact position of a target.

80
Q

What does passive remote sensing require?

A

Energy from the sun or thermal energy from the ground

Daylight (mostly)

81
Q

What does RADAR stand for

A

RAdio Detection And Ranging

82
Q

What wavelengths does RADAR use?

A

microwaves

83
Q

What defines Radar Altimeter? What is it used for?

A

Points straight down. Measures sea surface heights.

84
Q

Weather Radar. What can it do?

A

Images through clouds to create a 3D image of storms

85
Q

Radar Scatterometer. Sensor view, use?

A

Nadir view. Surface winds over the ocean

86
Q

Synthetic aperture radar (SAR) properties, what does it go through?

A

2D surface backscattering. Goes through vegetation and clouds to map.

87
Q

What are the 3 types of active radar scattering?

A

Smooth Surface (Specular Reflection), Rough Surface Scattering, Double Bounce

88
Q

Smooth Surface Scattering (Specular Reflection)

What does it pick out? Pixel color?

A

Pixels with little energy come back as black like roads or water features

89
Q

Rough Surface Scattering. Properties, pixel color?

A

Goes everywhere, most things. Grey pixels.

90
Q

Double Bounce Scattering. Properties, pixel color?

A

Bounces 2,3,4x before returning to sensor. White due to so much energy.

91
Q

How can you interpret backscatter images?

A

By knowing how microwaves hit the ground

92
Q

Synthetic Aperature Radar (SAR)

What problem does it solve and how?

A

Needs really big antenna for good resolution. Sends multiple pings off an object, holds them, and then reassembles into a single image with much better resolution

93
Q

How fast do microwaves move?

A

Speed of light

94
Q

What are the two directions energy can move out of a transmitter?

A

Horizontal or Vertical (polarized)

95
Q

What wavelengths produce higher resolution images in active RS?

A

Shorter wavelengths (higher frequency)

96
Q

What is SEASAT?

A
  1. First civilian SAR satellite.

Measures internal waves, currents, and storms

97
Q

What is Shuttle Radar Topography Mission (SRTM)?

A 
Feb 2000. 9 days..
Near complete global elevation data.
Released 90m (crazy for most world) and later 30m
98
Q

TerraSAR-X and TanDEM-X. What are they?

A

2 satellites working in tandem.
Releaseda 12m global dataset
Both bare Earth and DSM

99
Q

What are some uses of active remote sensing?

A

Environmental monitoring, hydrology, oceanography, radar altimeter, vessel tracking, oil spill monitoring

100
Q

What are the 3 types of passive RS scattering?

A

Rayleigh, Mie, and Non-selective

101
Q

What are the 3 types (levels) of spectral resolution?

A

Panchromatic (1 band)
Color (3 bands RBG)
Multispectral (4+)

102
Q

What is another name for a Near-Polar Orbit?

A

sun-synchronous.

103
Q

What are the 4 types of RADAR?

A

Altimeter, Weather, Scatterometer, Synthetic Aperture Radar (SAR)

104
Q

What wavelengths provide better penetration in Active RS?

A

longer wavelengths

105
Q

What does LiDAR stand for?

A

Light Detection and Ranging

106
Q

What is so great about LiDAR?

A

Produces detailed surface models bare Earth DEMS at submeter accuracy

107
Q

What is the basic process of LiDAR?

A

shortwave laser light transmitted then backscatter is recorded

108
Q

2 types of LiDAR

A

Aerial and Bathymetric

109
Q

What are the three types of LiDAR returns?

A

First return: highest feature on landscape
Middle return: vegetative structure
Last return: usually bare earth

110
Q

What doe SONAR stand for?

A

Sound Navigation and Ranging

111
Q

What is the basic process of SONAR?

A

transmission of sound waves through the water column and recording the energy backscattered from the bottom

112
Q

What do you use high and low frequencies for in Single Bean Echo?

A

High frequency = high detail, used in shallows

Lower frequency for deep water

113
Q

In multibeam backscatter, how can you tell hard bottoms from soft?

A

Hard bottoms reflect more energy than soft ones.

GIS (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions