QGIS – REMOTE SENSING QUIZ 3
TEST
Vector vs Raster - ANSWER Vector - Discrete data stores as point, line, and
polygon features
Raster - Contiguous data stores as a gridded array of cells (show elevation,
precipitation, temperature, imagery)
Imagery vs Raster Data - ANSWER Raster Data
- measurement within cell boundary
- interpolated value from a vector dataset
- stored in a geographic map projecction
Imagery
- cell is called a pixel -- not restricted to the boundaries of the cell
- every image has its own geometry related to the earth
Cell Size in Raster Data - ANSWER Smaller cells = more detail, larger file size
Larger Cells = less detail, smaller file size
What is remote sensing? - ANSWER Collecting information about an object
without being in direct physical contact with it.
Art and science of obtaining information about an object or phenomenon
through analysis of data that is obtained by a device that is not in contact with
the object of phenonmenon
Basic RS Facts - ANSWER - most remote sensing uses the electromagnetic
spectrum
, - human vision system is a remote sensing system that operates in a small
portion of the spectrum
- through scientific remote sensors are similar to human vision, they have
capabilities that extend beyond that of humans
Types of Imagery - ANSWER - many collection platforms
- many sensors or modalites
- more than a picture
- used for visualization and analyss
Electro-Opical (EO) magery - ANSWER -stores energy measurements
captured at a location
- images allow you to calculate the reflectance of an object to identify things
such as water, vegetation, concrete, and other objects
Imagery types or Modalites - ANSWER Literal Imager --- what you see
everyday (EO, PAN, COLOR, MS)
Nonliteral Imagery (Radar, TIR, Sonar, MS, Other)
Pixel -- The Smallest Unit of an Image - ANSWER Two-D array of pixels
arranged in columns nd rows create digital images
- pixel represents an area of the Earth's surface
- Pixel determines picture resolution
Ground Sample Distance (GSD) for a Pixel - ANSWER Distance between
pixel centers in ground units
- primary characteristics of imagery that determines the image quality
Active vs Passive Sensors - ANSWER Thermal
- passive
Radar
- active
TEST
Vector vs Raster - ANSWER Vector - Discrete data stores as point, line, and
polygon features
Raster - Contiguous data stores as a gridded array of cells (show elevation,
precipitation, temperature, imagery)
Imagery vs Raster Data - ANSWER Raster Data
- measurement within cell boundary
- interpolated value from a vector dataset
- stored in a geographic map projecction
Imagery
- cell is called a pixel -- not restricted to the boundaries of the cell
- every image has its own geometry related to the earth
Cell Size in Raster Data - ANSWER Smaller cells = more detail, larger file size
Larger Cells = less detail, smaller file size
What is remote sensing? - ANSWER Collecting information about an object
without being in direct physical contact with it.
Art and science of obtaining information about an object or phenomenon
through analysis of data that is obtained by a device that is not in contact with
the object of phenonmenon
Basic RS Facts - ANSWER - most remote sensing uses the electromagnetic
spectrum
, - human vision system is a remote sensing system that operates in a small
portion of the spectrum
- through scientific remote sensors are similar to human vision, they have
capabilities that extend beyond that of humans
Types of Imagery - ANSWER - many collection platforms
- many sensors or modalites
- more than a picture
- used for visualization and analyss
Electro-Opical (EO) magery - ANSWER -stores energy measurements
captured at a location
- images allow you to calculate the reflectance of an object to identify things
such as water, vegetation, concrete, and other objects
Imagery types or Modalites - ANSWER Literal Imager --- what you see
everyday (EO, PAN, COLOR, MS)
Nonliteral Imagery (Radar, TIR, Sonar, MS, Other)
Pixel -- The Smallest Unit of an Image - ANSWER Two-D array of pixels
arranged in columns nd rows create digital images
- pixel represents an area of the Earth's surface
- Pixel determines picture resolution
Ground Sample Distance (GSD) for a Pixel - ANSWER Distance between
pixel centers in ground units
- primary characteristics of imagery that determines the image quality
Active vs Passive Sensors - ANSWER Thermal
- passive
Radar
- active
