Digital Remote Sensing Systems

Question 1

What range of the EMS does optical sensors focus on?

Answer 1

400 - 2500nm range of EMS

Question 2

What are the 4 different types of Optical Sensors?

Answer 2

Electromagnetic scanners
Spectrometers
Pushbroom Scanners
Imaging Spectrometers

Question 3

Multispectral Scanner System (MSS)
What type of optical sensor is it?
What type of scanner?
What is the nominal resolution?

Answer 3

Multispectral scanner

• 1972
• Four Channel Scanner (wavelengths: 450 - 1100 nm)
• 80m resolution

Question 4

Thematic Mapper and Enhanced Thematic Mapper

What wavelength did it focus on?
Pixel Resolution?

Answer 4

1984
- number of bands increased to 7
Wavelengths : 450 - 2500nm

Pixel Resolution:30m

Question 5

How is AFOV achieved?

Electromechanical Scanner

Answer 5

through a rotating mirror.

Question 6

How is IFOV determined?

Electromechanical Scanner

Answer 6

IFOV is determined through the sampling rate of the electronic detectors

Question 7

What are some issues associated with Electromechanical data?

Answer 7

1. Mirror velocity profile variation

2. Scan line length variations.

Question 8

Push Broom Scanner

• How is each array programmed?

Can a multi-spectral image be constructed?

Answer 8

• A passive optical scanner
• Imaging elements are arranged in an array that is perpendicular to the direction of flight.
• Each array is programmed to record a certain portion of the spectrum.

Question 9

What does a Spectrometer gather?

How does it gather information?

Answer 9

Not used to acquire image data.

Gathers information about specific features of items.

Ex. can determine the reflectance spectra of leaves, grass, etc.

Gathers information through the use of a large number of charged coupled device (CCD)
- each CCD records energy information to a specific predetermined wavelength.

Question 10

The combination of the spectrometer and electromechanical scanner is the _____

Answer 10

Imaging Spectrometer

Question 11

How does an Imaging Spectrometer work?

What can it generate?

Answer 11

It combines the attributes of the spectrometer and the push broom scanner to generate a true image cube.

Question 12

Imaging Spectrometer

What dimensions are X,Y,Z

Answer 12

X &Y are spatial

Z is Spectral

Question 13

In terms of software what 5 modules compose a fully functional image

Answer 13

1 - input module
2 - Image correction module
3 - Image enhancement module
4 - Image Classification Module
5 - Output Module