Chapter 6 - Aerial + Satellite Images Flashcards
1
Q
This is the acquisition of surface data from remote distance
A
Remote sensing
2
Q
What are two ways images are collected for remote sensing?
A
Aircraft and satellites
3
Q
Remote sensing images serve as the basis for these
A
Maps
4
Q
What are the two types of data that remote sensing images provide?
A
Spatial and attribute data
5
Q
In what year was the first photo taken by balloon?
A
1858
6
Q
In what decade were the first wartime aerial photos taken?
A
1910s
7
Q
In what decade were the first aerial photography programs?
A
1940s
8
Q
In what decade were the first satellites for espionage, weather, and communications?
A
1960s
9
Q
In what decade was the first digital imagery for earth mapping?
A
1970s
10
Q
In what decade did free web images become available?
A
2000s
11
Q
What are the two main types of remote sensing?
A
Passive and active
12
Q
This type of remote sensing used electromagnetic energy from the sun
A
Passive
13
Q
Passive remote sensing images capture this from the Earth’s surface
A
Reflected wavelengths
14
Q
What two types of photos are included in passive remote sensing?
A
Aerial photos and satellite images
15
Q
Is passive remote sensing affected by night or clouds?
A
Yes
16
Q
In this type of remote sensing, an aerial platform directs an energy beam at the Earth’s surface
A
Active
17
Q
In active remote sensing, energy reflected from the Earth’s surface is captured via these
A
Scanners
18
Q
What are the two types of active remote sensing?
A
Radar and lidar
19
Q
This type of active remote sensing uses radio waves
A
Radar
20
Q
This type of active remote sensing uses laser light
A
Lidar
21
Q
Is active remote sensing affected by night or clouds?
A
No
22
Q
What are four benefits of remote sensing imagery?
A
- Large area coverage; 2. Extended spectral range; 3. Geometric accuracy; 4. Historical value
23
Q
What are at least four of six uses for remote sensing imagery?
A
- Navigation/mapping; 2. Forest inventory; 3. Geologic surveys; 4. Natural hazards; 5. Land use change; 6. Wildlife habitat assessment
24
Q
This describes the full range of radiation wavelengths
A
Electromagnetic spectrum
25
Remote sensing principally detects these two regions of EM wavelengths
Visible light and near infrared
26
What are three things that can happen to electromagnetic energy?
It can be reflected, absorbed, or transmitted
27
What can happen with absorbed electromagnetic energy?
It can be emitted
28
Do different substances absorb and reflect different wavelengths of electromagnetic energy?
Yes
29
This affects incoming electromagnetic energy from the sun/space
Atmosphere
30
What are two atmospheric components that affect electromagnetic energy?
Clouds/gasses/dust and water vapor
31
This atmospheric component reflects and absorbs energy
Clouds/gasses/dust
32
This atmospheric component absorbs energy and reduces transmittance
Water vapor
33
Visible light consists of these three colors/wavelengths
Red, yellow, blue
34
These describe reflectance of surface features to different wavelengths
Spectral reflectance curves
35
This describes photographs taken by aircraft
Aerial photography
36
Aerial photographs were first taken from these in the 1850s
Balloons
37
Aerial photography developed rapidly after the invention of this
Airplane
38
This is the measurement of photos
Photogrammetry
39
This is the identification of surface features from aerial photographs
Photo interpretation
40
What are at least three of four uses of aerial photos in GIS?
1. Source of accurate coordinates; 2. Provide spatial location of features; 3. Provide surface attribute data; 4. Serve as background layers in GIS
41
What are two types of cameras used in aerial photography?
Film and digital cameras
42
This type of camera used in aerial photography produces an image directed onto film emulsion
Film camera
43
What are two types of film cameras used in aerial photography?
Small format and large format
44
What are two sizes of small format cameras used in aerial photography?
35mm and 70mm
45
Which is more expensive, small format or large format film cameras?
Small format
46
Which produces higher quality images for aerial photography, small or large format film cameras?
Small format
47
What is the size of large format film cameras in aerial photography?
240mm
48
Large format film cameras are used on aircraft designed for this
Precise flight
49
What are small format aerial photography film camera images used for?
Qualitative surveys
50
Do large format film cameras for aerial photography have low distortion?
Yes
51
What are large format aerial photography film cameras used for?
Geometric mapping
52
These are replacing film cameras for aerial images
Digital cameras
53
Digital cameras use this to detect different wavelengths
Scanning element
54
How is data from digital cameras recorded?
In long continuous strips
55
Digital cameras eliminate the need for this
Scanning film into digital format
56
Large format cameras print these onto photos
Fiducial marks
57
What are three types of film used in aerial photography?
Panochromatic, color, infrared
58
This type of film is sensitive to a range of visible light and is commonly used for many purposes
Panochromatic
59
This type of film is inexpensive and provides good resolution
Panochromatic
60
This type of film depicts imagery in natural color and is the most common choice for map projects
Color
61
This type of film detects variation in infrared wavelengths
Infrared
62
This type of film is high contrast and small differences in reflectivity show up as sharp color differences
Infrared
63
This type of film is good for vegetation analysis, but must be taken "leaves-on"
Infrared
64
What are the two types of infrared film?
Black and white and false-color
65
Aerial films usually include this that records flight and camera info
Data strip
66
These are used to produce 3D images of surfaces
Stereo photos
67
Adjacent overlapping images are called this
Stereopairs
68
Stereo photos are used to draw these
Elevation contour lines
69
Stereo photos can be used to remove this from photos
Relief distortion
70
Overlap in this creates stereo photos in aerial photography
Flight path
71
Onboard computers aid in these for aerial photography
Precise flight patterns
72
Raw aerial photos contain these
Distortions
73
What are at least three of four types of aerial photograph distortions?
1. Relief displacement; 2. Camera tilt; 3. Camera/film/lens errors; 4. Atmosphere
74
Raw photos have this view, as they are not orthographic
Perspective view
75
This creates distortion caused by terrain and buildings
Relief displacement
76
In photos distorted by relief displacement, tall objects appear to lean outward and radiate from this
Principal point
77
How does displacement change with distance from a principal point in relief displacement distortion?
Displacement rises
78
These objects have more displacement in relief displacement distortion
Taller objects
79
What are two aspects of a photo that relief displacement affects?
Angles and distances
80
This is not constant in photos distorted by relief displacement
Photo scale
81
Distortion-corrected aerial images have this view
Orthographic view
82
This is in line with the camera's optical axis in an aerial photograph
Principal point
83
Where are points above the datum displaced?
Outward
84
Where are points below the datum displaced?
Inward
85
This type of distortion occurs when the optical axis is not vertical and causes apparent convergence of distant objects
Camera tilt
86
Photo contracts specify how much tilt?
< 3 degrees
87
These help reduce camera tilt
Camera stabilizers
88
Camera tilt data are recorded on this
Data strip
89
This the effect of terrain and tilt on geometric accuracy
Tilt convergence error
90
Does tilt convergence error increase or decrease with decreasing map scale?
Increase
91
Flaws in these can cause displacement
Lenses
92
This camera part can distort the focal plane
Camera platten
93
What can happen to film to produce errors?
Shrinking/swelling
94
Are camera/film/lens errors smaller on large format cameras?
Yes
95
This source of photo distortions is important for high altitude images
Atmosphere
96
This process corrects errors of tilt and relief displacement
Photo rectification
97
What are two things required by the photo rectification process?
Stereopairs and special equipment
98
Photo rectification produces this, a photo that is geometrically accurate and has uniform scale
Orthophoto
99
This machine was initially used to produce orthophotos
Orthophotoscope
100
These are now used to produce orthophotos
Modern photogrammetric workstations
101
Satellite scanners contain these to image the Earth's surface
Detector arrays
102
Satellite detectors convert electromagnetic radiation into this
Recorded signal
103
In satellite imagery, a detector array is directed toward Earth and a scanner does this
Sweeps surface
104
Imaging satellites occupy this type of orbit to ensure the field of view is always at the same time of day
Sun-synchronous
105
Do satellite imaging scanners have a broader electromagnetic range than aerial cameras?
Yes
106
Why do satellites have a broader range than aerial cameras and produce less relief distortion?
High perspective results in optical axis near vertical
107
Satellite image data requires this, at higher costs than aerial photography
Special processing
108
What are at least three of four lower resolution satellite imagery systems?
1. Landsat; 2. Moderate Resolution Image Sensor; 3. Vegetation; 4. SPOT
109
This is the longest running remote sensing system, with over 30 years of continuous coverage
Landsat
110
In what year did Landsat begin as a NASA system?
1972
111
In what year did Landsat switch from a NASA system to NOAA system?
1979
112
How many Landsat satellites have there been?
7
113
How many Landsat satellites are currently operating?
2
114
What is Landsat's return time for mid-latitudes?
17 days
115
What are the two Landsat satellites?
Multispectral scanner and thematic mapper
116
This was the first satellite land scanner
Landsat's multispectral scanner
117
How many bands does Landsat's multispectral scanner have?
5
118
What is the resolution of Landsat's multispectral scanner?
80 m
119
What two types of electromagnetic radiation does Landsat's multispectral scanner detect?
Visible and near infrared
120
How many bands does Landsat's thematic mapper have?
7
121
What three types of electromagnetic radiation does Landsat's thematic mapper detect?
Visible, near-infrared, mid-infrared
122
What is the resolution of Landsat's thematic mapper?
30 m
123
What resolution scanner does the newest Landsat thematic mapper add?
15 m panochromatic
124
Satellite images are catalogued using these
Scene index maps
125
This satellite imaging system is a NASA system with a wide range of electromagnetic radiation, from visible to thermal
Moderate Resolution Image Sensor (MODIS)
126
What is the resolution range of MODIS?
250-1000 m
127
What is the return time for MODIS at 1000 m resolution?
2 days
128
This imaging satellite was developed by the French government
Vegetation
129
What two wavelength bands does the Vegetation satellite collect?
Visible and infrared
130
What is the resolution of the Vegetation satellite?
1150 m
131
How many kilometers does the Vegetation satellite cover?
2400 km
132
This imaging satellite was developed by the French government and started in 1986
SPOT
133
What two types of images are taken by SPOT's scanners?
Panochromatic and multispectral
134
What is the panochromatic resolution of SPOT's scanners?
2.5-10 m
135
What is the image extant of SPOT?
60 x 60 km
136
Can SPOT take stereophotographs?
Yes
137
What resolution is required for a satellite imagery system to be considered high resolution?
<1 m
138
High resolution satellite systems can record these two types of data
Panochromatic and multispectral
139
What are three reasons why high resolution satellite systems are replacing aerial photos for many needs?
1. Resolution is now close to aerial imagery; 2. Wider electromagnetic range/extent; 3. Easier distortion correction
140
Are all high resolution satellite imagery systems commercial?
Yes
141
What are four examples of high resolution satellite systems?
IKONOS, QuickBird, Worldview, GeoEye
142
What are two types of active remote sensing?
RADAR and LIDAR
143
In this type of active remote sensing, satellites send radio waves to the Earth's surface and record reflection
RADAR
144
RADAR is carried on these
Airplanes
145
These two regions have RADAR satellites in operation
US and Europe
146
What two types of mapping is RADAR used for?
Topography and cover type mapping
147
This obtained full global elevation data in 2000
Shuttle Radar Topography Mission
148
In this type of active remote sensing, satellites direct a laser light to the Earth's surface and record reflection
LIDAR
149
What is the resolution of LIDAR?
10 cm
150
What are commercial LIDAR systems used for?
Elevation data
151
What two applications are LIDAR systems being tested for?
Vegetation typing and water quality
152
Most LIDAR are carried on these, though satellite systems are in development
Aircraft
153
Which form of remote sensing traditionally had higher resolution: aerial imaging or satellite imaging?
Aerial imaging
154
Which form of remote sensing can provide electromagnetic data not available to the other?
Satellite imaging
155
Which form of remote sensing has the advantage of using digital data?
Satellite imaging
156
These are eliminating the digital advantage of satellite imaging
Digital aerial cameras
157
Do remote sensing images often require interpretation?
Yes
158
This is the science of identifying objects in images
Photo interpretation
159
Photo interpretation often requires this
Ground truthing
160
What are at least five of eight types of photo elements that aid in identification?
1. Tone brightness/color; 2. Relative size; 3. General object shape/outline; 4. Texture; 5. Spatial arrangement patterns; 6. Light/shadows; 7. Geographic location patterns; 8. Association of neighboring objects
