Lecture 1

Question 1

What is Remote sensing?

Answer 1

The science of acquiring data about earths surface without being in contact with it

Question 2

How is RS done?

Answer 2

sensing and recording reflected or emitted energy and processing, analyzing and applying that information.

Question 3

Basic principle of RS

Answer 3

Electromagnetic radiation- remote sensors measure radiation

Question 4

Advantages to RS

Answer 4

• No physical contact: min cost ->max safety
• Synoptic: covers large area
• Unobtrusive: remote areas
• Systematic: predictable, repeatable, continuous
• Global coverage
• Accurate: reliable repeatable data

Question 5

Disadvantages to RS

Answer 5

• Accuracy: resolution, distance, not phsyically there
• Expensive
• Prone to interference (clouds, storms, time of day)
• Indirect measurement of light (derived variables- reflection)
• Data is interpreted: pixels can be interpreted differently

Question 6

What to consider when choosing a sensor platform?

Answer 6

• cost to operate
• desired spatial coverage
• spatial resolution
• desired temporal resolution

Question 7

What is remote sensing process? (6 levels)

Answer 7

1. Energy source or illumination (Electromagnetic radiation)
2. Radiation comes in contact with the Atmosphere (interact/interfere)
3. Interaction with target; energy passes through atmosphere
4. Energy is recorded by sesnor: energy has been scattered or emitted from target: sensor collect & records
5. Transmission, Reception, and Processing of data
6. Interpretation & Analysis: processed image is interpreted (visually or digitally) to extract information about the target
7. Application: apply information from imagery of target

Question 8

What is the visible light spectrum (nm)

Answer 8

400nm -800nm

Question 9

What is a passive sensor

Answer 9

Sensors that detect naturally emitted radiation by an object, area, or phenomenon
- Reflected Solar Radiation (EMR)
- Emitted Thermal energy (Heat)

Question 10

What is an active sensor

Answer 10

energy directed at an object by the sensor which is then reflected/ scattered
- backscattered radiation

Question 11

Why is RS critical in Earth Observation

Answer 11

collection of measurements over large surfaces, change analysis

Question 12

Uses of RS in Earth Observations

Answer 12

• Location
• Topography
• Vegetation Variables
• Surface temperatures
• Geology
• Atmosphere (weather)
• Water (bathymetry)
• Snow & Ice (Glaciers)
• Volcanism
• Land use/ land cover