Section 3.1 Flashcards
Instantaneous field of view refers to ….
Smallest unit recordable for a sentence
Identify the variables:
D = HB
D = pixel size H = sensor altitude B = instantaneous field of view
Angular field of view is ….
The apparent field of view of a sensor
Optical sensors cover _____ to _____ nm on the electromagnetic spectrum
400, 2500
True or false
An electromechanical scanner is an active scanner
False
An electrochemical scanner is a _______ scanner with wide channels
Passive
The angular field of view of an electrochemical scanner is achieved by a _____________
Rotating mirror
True or false
Electromechanical scanners have large spatial coverage
True
Two issues associated with electrochemical scanners are:
Mirror velocity profile variation
Scan line length variation
What type of scanner is a Landsat?
Electrochemical
What is a limiting factor when looking at image interpretation?
Resolution/pixel size
True or false
Landsat is a multispectral scanner
True
What wavelengths do a Landsat pick up in 1972 and what was the resolution?
Blue, green, red, NIR
80 m
A pushbroom scanner is a _______ scanner using a _________ linear detector
Passive, discrete
Pushbroom scanner uses …..
Charged couple devices
Charged couple devices are used in ________ scanners and are oriented _______ to the flight direction
Pushbroom, perpendicular
When you use a multiple array of charged couple devices, each programmed to different wavelengths you get a
Multispectral image
Give two examples of a pushbroom scanner.
AISA
CASI
What is the resolution of a AISA image?
2m
True or false
Spectrometers acquire image data
False
What are four sensor types?
Electrochemical
Pushbroom
Spectrometer
Imaging spectrometer
True or false
Spectrometers are usually used in aerial photography.
False, most are ground based
What does CCD mean?
Charged couple device
Spectrometers can determine reflectance spectra of …
Leaves, grass, trees
True or false
Spectrometers are only used on the ground
False, they can be airborne
Spectrometers use a large number of _______ programmed to specific wavelengths
CCD
Spectrometers cover a very _______ area, but provide _________ spectral information.
Small, continuous
True or false
Imaging spectrometer is a combination of pushbroom scanners and spectrometers but not electrochemical scanners.
False, it is a combination of all three
Imaging spectrometer creates a true image ______.
Cube
In a imaging spectrometer what do the axis of the image cube represent?
X and y axis are spatial dimensions
Z axis is spectral
Imaging spectrometer uses a two dimensional Charged couple device(CCD) what is another name for this?
Complimentary metal-oxide-semiconductor matrix (CMOS)
And imaging spectrometer collects ________ spectral data across a _________ spectral range.
Large, large
Imaging spectrometers collect data over a _______ area with _______ spatial resolution.
Large, high
Image processing systems (_________) are fundamental tools for remote sensing.
Computers
Define radiometric resolution.
The ability of remote sensing systems to distinguish changes in electromagnetic energy
Finer radiometric resolution means _______ sensitivity
More
Radiometric resolution determines the range of _________
Possible digital numbers
Greater data depth means greater….
Precision.
What is the difference between real and integer storage and what are the benefits of real?
Integer storage is 8-bit whole numbers
Real storage is 32-bit with fractions.
Real is advantageous because there is finer definition.
What is a histogram?
A chart that shows the frequency distribution of data.
