Midterm of DOOM Flashcards
Define Remote Sensing
the science, technology and art of obtaining information about an object area or phenomenon without touching it.
What is electromagnetic energy?
elector magnetic energy is carried by electromagnetic radiation by transmitting the oscillation of electromagnetic fields through space or matter
4 examples of Electromagnetic energy
Infrared
Visible
Ultraviolet
Microwave
Define Scattering
the unpredictable diffusion of radiation by particulates
Define Absorption
the loss of energy to constituents
How does the atmosphere affect spectral responses patterns?
The atmosphere absorbs electromagnetic energy and causes the resulting image to be dim.
Name characteristics of an ideal remote sensing system
- uniform energy source
- non-interfering atmosphere
- super sensor
- unique energy matter interaction of the earths surface
- real time data processing
- multiple data users
Name 4 types of resolutions
- Spectral
- Spatial
- Temporal
- Radiometric
Describe Spectral Resolution
how much of the electromagnetic spectrum can the sensor differentiate between
Describe Spatial Resolution
the size of the pixel projected on the ground
Describe Temporal Resolution
frequency if data acquisition over an area.
Describe Radiometric Resolution
the ability of the sensor to decipher between electromagnetic energy acquired (the difference between pixel values)
What is the difference between passive and active sensors?
Passive sensors only receive information while active sensors send and receive
Define Geo-stationary satellite
a satellite that stays over a single position of the ground
Define sun-synchronous satellite
satellite stayes on the sunny side of the earth and crosses the equator at the same time every day.
5 advantages of Aerial photography
- Improved vantage point
- Capability to stop action
- Permanent record
- Broadened spectral sensitivity (beyond what the eye can see)
- Increased spatial resolution
List 3 types of film
Black and white
Colour Film
Colour infrared film
List and describe 2 types of black and white film
Panchromatic - UV and Visible spectrum
Infrared - UV, VIS and NIR
Describe colour film
layer film, each layer is sensitive to a different range of the spectrum
What bands colour Infrared film sensitive to
NIR, red and green of visible spectrum
4 types of filters used in arial photography
- High Pass
- Band Pass
- Interference
- Antivignetting
3 types of Aerial cameras
Frame
Panoramic
Continuous strip
What is the difference between small and large scale photographs?
Large scale covers a covers a small area in greater detail
Small scale covers a large area with less detail
What is GCP
Ground Control points
What are the 3 techniques to enhance an image and describe them
Grey level thresholding - brak the hitogram into two parts (true / false) black / white
Contrast Enhancement - Linear and Gaussian
Colour enhancement
What is digital image processing
a collection of computerized techniques for the manipulation of digital images
What are the 4 p’s in processing
Pre-processing
Processing and analysis
Post Processing
Presentation
What are the steps in geometric correction using GCP’s?
- determine GCP’s
- Apply transformation equation
- root mean square Error
- resampling
- evaluation
