Introduction to Remote Sensing

Question 1

What is ‘remote sensing’?

Answer 1

Remote Sensing is the science & technology of acquiring information about the earth’s surface & atmosphere using sensors on airborne or space-borne platforms

Question 2

What are the elements of a remote sensing process? (Ie: the 9 elements shown in the slideshow illustration)

Answer 2

• Energy Source (ie. sun)
• Incoming electromagnetic radiation (EM) - from Energy source
• Target (eg. vegetation)
• Sensor
• Reflected energy (from target to sensor)
• Emitted energy (from ground to sensor)
• Data relay satellite (recieves info from sensor)
• Ground recieving station (revieces info from sensor and data relay satellite)
• Data products (available after ground recieving station info has been processed)

Question 3

What do sensors do?

Answer 3

Sensors – detect & record energy “signals” from features on the
earth/atmosphere

Question 4

Data from sensors can be collected via which two formats?

Answer 4

i) Analog format – aerial photos, video data; converted into digital format by scanning
ii) Digital format – pixels of Brightness values (BV); directly used by input to computers

Question 5

True or false: remote sensors can only collect data from within the visible light spectrum.

Answer 5

False

Question 6

Specific portions of the
electromagnetic spectrum (EMS) are referred to as what?

Answer 6

Bands

Question 7

What kind of spatial-resolution imagery is typically used at a continental or global scale?

Answer 7

Coarse spatial-resolution imagery

Question 8

What kind of spatial-resolution imagery is typically used at a local scale?

Answer 8

High spatial resolution

Question 9

What kind of spatial-resolution imagery is typically used at a regional (not local) scale?

Answer 9

Medium spatial resolution

Question 10

What is a remote sensing technology with a relatively quick revisit time?

Answer 10

3 examples:

• GOES satellite (30 min.)
• NOAA AVHRR local-area coverage (½ day)
• MeteoSat 2nd Gen. (15-min.)

Question 11

GPS uses what method to determine the position of a receiver?

Answer 11

Trilateration (Illustration: 3 satellites with the GPS reciever in the middle)