Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

GIS > Exam 3 > Flashcards

Exam 3 Flashcards

(113 cards)

Start Studying
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
Define Band
Range of wavelengths that may be measured by a remote sensing device
26
What are brightness values?
the energy measured at a single pixel according to a predetermined scale (what RS is measuring)
27
What bands can be captured by RS? In order from shortest to longest wavelength?
Visible Light (Blue, Green, Red), Near Infared (NIR), Shortwave Infared (SWIR), Thermal infared (TIR)
28
What are the 4 types of resolution? What do they measure?
Spatial Resolution- what level of detail Spectral Resolution- what colors or bands Temporal Resolution- revisit time Radiometric Resolution- color depth
29
What is the temporal resolution of the current Landsat?
16 days
30
Define Off-nadir viewing
Capability of a satellite to observe areas other than the ground directly below it.
31
Blue Band: range and uses
0.4-0.5 um Deep water imaging Smoke plumes, atm haze, clouds Clouds, snow, rock
32
Green Band: range and uses
05.-0.6 um Plant vigor and vegetation Algal and cyanobacterial blooms Urban recreation (parks)
33
Red Band: range and uses
0.6-0.7 um Soil types and geological features Chlorophyll absoption (NDVI) Built vs natural environment
34
IR (infared): range and subsets
0.7-100 um | NIR, SWIR, TIR
35
NIR (near infared): range and uses
``` 0.7-1.3 um Biomass content Archaeological sites NDVI Vegetation Land/water boundaries ```
36
SWIR (shortwave infared): range and uses
``` 1.3-3.0 um Moisture content Cloud/smoke penetration Mineral exploration Water properties (turbidity) ```
37
TIR (thermal infared): range and uses
``` 3-14 um Volcano activity Urban heat Weather prediction Wildfire tracking ```
38
Visible Light spectrum range
0.4-0.7 um
39
UV range
0.01-0.4 um
40
# Define NDVI What is its range?
Normalized difference Vegetation Index. NDVI= (NIR-Red)/(NIR+Red) Ranges from -1 to +1 (-1 means nothing is growing and +1 means healthy)
41
What was Sputnik? | Year, country, what did it do?
1957, USSR, first artificial satellite. | Beeped for 3 weeks then died. Officially started the space race.
42
What was the International Geophysical Year? | Legacy?
1957-1958 67 countries developing technology for space and elsewhere. Legacy: atm studies, midocean ridges, radiation belts, Antarctic Treaty
43
What was the fallout from Sputnik 1? What did it lead to?
Public panic, not government | Directly led to NASA, lunar program, DARPA, and a renewed interest in math and science in education.
44
What was Explorer 1? | Year, country, what did it do?
1958, USA, our first sat. Returned data for 4 months. Smaller, lighter, and longer lasting than sputnik
45
What was the Corona Program? | Years, purpose
1952-1972 Took BW images of different places on Earth (Russian reconnaissance 1960) Ejected film canisters, salt plug. Many failures at first.
46
What was Skylab? | year, for what, for whom
1973 Largest manned space stations 24 weeks, hundreds of missions (science nerds)
47
What is Kennen KH-II? | year, purpose, for whom
``` 1976-present? Defense purposes First electronic imaging sat that could send real-time. KH= keyhole (spying) No one knows what they look like. ```
48
Landsat | What is it, years, for whom
Landsat is the longest running continuously operative remote sensing platform. 1972-present. Landsat 9 to launch in 2020 All data now freely available.
49
LandSat 7 | What major issue does it have?
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
LandSat Ground Station Network Where? Problems?
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
LandSat Catalog. | What is it? how do you use it?
World wide Reference system using paths and rows to find LandSat scene (RI fits into one)
52
Define EROS
Earth Resources Observation Science Center. Serves as a downlink station for satellite imagery.
53
What is the Copernicus Program?
EU's Earth Observation Program. | Sentinel 1A/B-6 (current)
54
Define Satellite constellation. | What does this do?
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
Sentinel 1A/B | What does it do?
Sea ice and land movement. | Can make a banthometric map.
56
Sentinel 2A/B | What does it do?
Similar applications to LandSat multispectral, revisit time 5 days Better resolution than LandSat 8
57
Sentinel 3A/B | What does it do?
Marine oriented. Land and ocean color. | Revisit time 1-2 days.
58
Sentinel 4, 5, 6 | What do they do?
Yet to be released. Sentinel 4: air quality Sentinel 5: atmosphere Sentinel 6: more advanced Radar
59
What are the two biggest government satellite programs?
LandSat (USA), Sentinel (EU)
60
What was the Land Remote Sensing Policy Act?
1992. Allowed US companies to operate imaging satellites in space.
61
IKONOS-1 | Years, what did it do?
1999-2015 1st commercial high resolution sensor Revisit time 3 days (much better than LandSat 7)
62
SPOT | Years, what did it do?
Originally French gov backed financially 1986, 2014 Similar to others in function.
63
World View-3 | Years, what was unique
launched 2014. 1ft resolution, 1 day revisit. Can point mirror to task the satellite.
64
What are the trends in satellite technology?
``` Better resolutions (temporal, spectral, spatial, and radiometric) Spatial resolution is getting finer but swath width also becomes smaller. ```
65
CubeSat | Years, what is unique
Launched 2003 small block units, 1-6 units Off shelf components, cheap, reduces research costs
66
SkySat and PlanetScope | unique properties
SkySat: cube concept but fridge size. Can get video. Planet Scope: doves and flocks. Huge coverage.
67
CZCS | Define, years, purpose
Coastal Zone Color Scanner 1978-1986. First ocean color imagery.
68
Sea-WIFS | Years, unique properties, purpose
1997-2010 Global bio data. Changed sensor angle as it passed over equator to avoid glint and sensor blowout.
69
NASA's Earth Observing System | Program name, years, type of satellites, issues
MODIS program. Terra and aqua sats, 1999 and 2002, overdue. Gaps between swaths but 36 bands
70
VIIRS | Years, purpose
SUOMi NPP partnership to replace MODIS No more gaps with better coverage. 2011.
71
What are some things you need to specify to someone who resells imagery?
Which satellite, what resolution, what temporal component, area of interest, how many clouds, etc
72
What does the cost of satellite imagery depend on?
Minimum order size, which satellite, if it's already in archive, etc
73
How do you manipulate the temporal component to get a better picture?
averaging days together, or even months. | Months over years creates a composite with less details but a much cleaner picture.
74
What data level do most typically ask for
Level 3
75
Define SDB | Who uses it? What are the limitations?
Satellite Derived Bathymetry Used by NOAA and others to remap nautical maps, especially when coupled with LandSat data Limited by turbidity
76
What are some examples of LandSat 8 uses. Think TIR
California wildfires, Yellowstone new hotspot formation
77
How does active remote sensing use energy?
Sensor generates its own electromagnetic energy directed at the target
78
What is received by an active remote sensor?
backscattering
79
What are some advantages of active remote sensing? | 4
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
What does passive remote sensing require?
Energy from the sun or thermal energy from the ground | Daylight (mostly)
81
What does RADAR stand for
RAdio Detection And Ranging
82
What wavelengths does RADAR use?
microwaves
83
What defines Radar Altimeter? What is it used for?
Points straight down. Measures sea surface heights.
84
Weather Radar. What can it do?
Images through clouds to create a 3D image of storms
85
Radar Scatterometer. Sensor view, use?
Nadir view. Surface winds over the ocean
86
Synthetic aperture radar (SAR) properties, what does it go through?
2D surface backscattering. Goes through vegetation and clouds to map.
87
What are the 3 types of active radar scattering?
Smooth Surface (Specular Reflection), Rough Surface Scattering, Double Bounce
88
Smooth Surface Scattering (Specular Reflection) | What does it pick out? Pixel color?
Pixels with little energy come back as black like roads or water features
89
Rough Surface Scattering. Properties, pixel color?
Goes everywhere, most things. Grey pixels.
90
Double Bounce Scattering. Properties, pixel color?
Bounces 2,3,4x before returning to sensor. White due to so much energy.
91
How can you interpret backscatter images?
By knowing how microwaves hit the ground
92
Synthetic Aperature Radar (SAR) | What problem does it solve and how?
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
How fast do microwaves move?
Speed of light
94
What are the two directions energy can move out of a transmitter?
Horizontal or Vertical (polarized)
95
What wavelengths produce higher resolution images in active RS?
Shorter wavelengths (higher frequency)
96
What is SEASAT?
1978. First civilian SAR satellite. | Measures internal waves, currents, and storms
97
What is Shuttle Radar Topography Mission (SRTM)?
``` Feb 2000. 9 days.. Near complete global elevation data. Released 90m (crazy for most world) and later 30m ```
98
TerraSAR-X and TanDEM-X. What are they?
2 satellites working in tandem. Releaseda 12m global dataset Both bare Earth and DSM
99
What are some uses of active remote sensing?
Environmental monitoring, hydrology, oceanography, radar altimeter, vessel tracking, oil spill monitoring
100
What are the 3 types of passive RS scattering?
Rayleigh, Mie, and Non-selective
101
What are the 3 types (levels) of spectral resolution?
Panchromatic (1 band) Color (3 bands RBG) Multispectral (4+)
102
What is another name for a Near-Polar Orbit?
sun-synchronous.
103
What are the 4 types of RADAR?
Altimeter, Weather, Scatterometer, Synthetic Aperture Radar (SAR)
104
What wavelengths provide better penetration in Active RS?
longer wavelengths
105
What does LiDAR stand for?
Light Detection and Ranging
106
What is so great about LiDAR?
Produces detailed surface models bare Earth DEMS at submeter accuracy
107
What is the basic process of LiDAR?
shortwave laser light transmitted then backscatter is recorded
108
2 types of LiDAR
Aerial and Bathymetric
109
What are the three types of LiDAR returns?
First return: highest feature on landscape Middle return: vegetative structure Last return: usually bare earth
110
What doe SONAR stand for?
Sound Navigation and Ranging
111
What is the basic process of SONAR?
transmission of sound waves through the water column and recording the energy backscattered from the bottom
112
What do you use high and low frequencies for in Single Bean Echo?
High frequency = high detail, used in shallows | Lower frequency for deep water
113
In multibeam backscatter, how can you tell hard bottoms from soft?
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