Brainscape's Knowledge GenomeTM

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


See full index

Remote Sensing > Midterm 1 > Flashcards

Midterm 1 Flashcards

1
Q

What is Remote Sensing

A

Obtaining info about an object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with it.

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

Electromagnetic Spectrum

A 
Cosmic Rays
Gamma Rays 10^-6 microns
X-Rays 10^-4 microns
Ultraviolet 0.1 microns
Visible .4 to .7 microns
Near-IR 1 micron
Mid-IR
Thermal IR 10 microns
Microwave 10 cm
TV and Radio 100 m
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Frequency

A

Cycles per second

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

Stefan-Boltzmann Law

A

All matter above absolute zero continuously emits EM radiation and the amount of radiation is a function of the surface temperature of the object

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

Black body

A

Hypothetical ideal radiator that totally absorbs and reemits all energy incident upon it.

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

Wein’s Displacement Law

A

As the temperature increases, there is a shift toward shorter wavelengths. (Causes Red-Shift because as objects in the universe recede they cool)

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

Remote Sensing Steps

A 
Energy source
Radiation and the atmosphere
Interaction with the target
Recording of energy by the sensor
Transmission, reception, processing
Interpretation and analysis
Application
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Types of Atmospheric Effects

A

Scattering

Absorption

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

Atmospheric Scattering

A

Rayleigh EM > particle
Mie EM = particle
No selective EM < particle

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

Rayleigh Scatter

A

EM > particle
Shorter wavelengths more susceptible
Why the sky is blue: because blue light scatters more.
At sunset and sunrise light goes through more atmosphere so more colors are scattered.

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

Causes of atmospheric absorption

A

Water vapor
Carbon dioxide
Ozone

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

Atmospheric Windows

A

Wavelength ranges that are trans missive of EM spectrum

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

Energy interactions with surface features

A

Reflection
Absorption
Transmission

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

Spectral Reflectance

A

The percent of incident energy that is reflected from a surface.

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

What causes different types of Reflection?

A

Surface roughness.
Specular vs diffuse reflectors.
Roughness is relative to wavelength.

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

Radiance

A

Brightness on the image - the sum of light coming from the object and atmospheric scatter.

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

EM Detection Methods

A

Photographic

Electronic

18
Q

Photograph vs Image

A

Analog vs anything

19
Q

Ground Truthing Goals

A

Interpretation aid
Sensor calibration
Information verification

20
Q

Advantages of aerial photography

A 
Improved vantage point
Snap shot in time
Permanent records
Broad spectral sensitivity
Resolution and geometric fidelity
21
Q

Image focus parameters

A

Focal length
Distance between lens and object
Distance between lens and image plane

22
Q

Color Infrared

A

Blue: blocked (black)
Green: blue
Red: green
IR: Red

23
Q

Digital Photography

A

Use of a complex array of photodiodes to image individual pixels

24
Q

Laser scanner

A

Emits an EM pulse and then reflected pulse is analyzed

25
Q

Photogrammetry

A

Handheld camera and range pole.

Two images, both with range pose images.

26
Q

Resolution

A

Minimum separation distance for observer to distinguish 2 objects

27
Q

Flight line issues

A

Tilt
Altitude change
Crab
Velocity changed

28
Q

Aerial photo notations

A

Fiduciary mark

Principle point

29
Q

Multispectral Imagery

A

Acquisition of imagery by simultaneous scanning through several spectral bands.

30
Q

Across-track scanning (whisk room)

A

Oscillating mirror scans at right angles to flight path.
Long strips of successive scan lines
Instantaneous field of view
Multi-spectral

31
Q

Instantaneous Field of View

A

The area the scanner sees at any instant in time.
Cone angle
Spatial resolution distance increases at the edges of the image (equal to pixel size)

32
Q

Pixel

A

Records the average spectral Reflectance of an area.

33
Q

Along-track scanning (pushbroom)

A

Uses a linear array of stationary CCD detectors to image a swath beneath the platform as it moves forward.
Each detector looks at a single spectrum.

34
Q

Spectral Resolution

A

The number, wavelength, and width of spectral bands used by the sensor
Multi-spectral: wide bands
Hyper spectral: narrow bands

35
Q

Radiometric Resolution

A

The number of brightness levels a sensor can record within a given wavelength.
Measured in bits

36
Q

Resolution balancing act

A

Small IFOV increases spatial resolution
Small IFOV reduces Radiometric resolution
Increasing Radiometric resolution reduces spectral resolution

37
Q

Temporal resolution

A

A function of how often a sensor flies over the object of concern and obtains imagery

38
Q

Thermal Scanner

A

3-5 microns and/or 8-14 microns
Quantum or photon detectors (rapid response)
Uses mirror

39
Q

Emissivity

A

How well the object radiates energy compared to the black body

40
Q

Forward-Looking IR (FLIR)

A

Oblique angles of the ground

Finding targets

Remote Sensing (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions