Remote Sensing & R.S. Products Flashcards
What are the 4 components of Incident Radiation?
1) Transmission
2) Emission
3) Absorption
4) Reflection
What are the 3 remote sensing ranges?
1) Visible Light & Reflective IR
2) Emitted & Thermal IR
3) Microwave
What are the 7 steps of the remote sensing process?
1) Source of radiation (Sun)
2) Incident radiation
3) Target
4) Reflection
5) Sensor
6) Processing
7) Product
What are the 3 sources of energy?
1) Sunlight
2) Objects
3) Sensors
What is the difference between a passive and an active sensor?
A passive sensor uses existing (ambient) energy; an active sensor generates its own energy
The total area that can be captured by a sensor is its…
Field of Regard (FOR)
The area perceivable by the sensor at a particular time instant is its…
Field of View (FOV)
The area actually imaged by the sensor is its…
Sensor swath
What are the 4 types of sensor resolution?
1) Spatial
2) Spectral
3) Temporal
4) Radiometric
The definition of spatial resolution:
The finest detail distinguishable in an image, measured in meters, i.e. how many meters are depicted per pixel (1m resolution much better than 30m).
Spatial resolution is aka…
Instantaneous FOV
The definition of radiometric resolution:
The ability to detect differences in energy magnitude. Measured in bits (more bits=more levels of brightness detected=better resolution).
The definition of spectral resolution:
Differentiation between distinct wavelengths of received EM radiation
The definition of temporal resolution:
The frequency at which data are captured for a specific place, i.e. how often images are taken.
The definition of revisit rate:
The time between imaging opportunities for a given point on the Earth’s surface, i.e. how long until a satellite flies over the same spot again.
What type of resolution information involves dimensional characteristics (location, size, shape, number, motion, surface structure)?
Spatial info
What type of resolution information involves the total amount of radiant energy (emissivity, reflectivity, type material, chemical composition)?
Radiometric (intensity) info
What type of resolution information involves radiation as a function of wavelength (temperature, resonance, type material)?
Spectral info
What type of resolution information involves time-changing characteristics (sensor geographical/orbital characteristics/capabilities)?
Temporal info
What are the 4 bands of IR, in order of increasing wavelength?
1) NIR
2) SWIR
3) MWIR
4) LWIR
What are the remote sensing EMR bands, in order of increasing wavelength (decreasing freq)?
Visible
NIR
SWIR
MWIR
LWIR
Microwaves: EHF, SHF, UHF
Which band(s) can analyze crops & vegetation and detect camoflage?
NIR & SWIR
Which band(s) can measure thermal radiation?
MWIR & LWIR
Shortwave/high freq=
_____ detail; _____ penetration
More; less
Longwave/low freq =
_____ detail; _____ penetration
Less; more
Which microwave band offers high spatial resolution and provides imagery day or night?
EHF
Which microwave band can penetrate heavy weather, smoke, fog with good (but not great) spatial resolution?
SHF
Which microwave band offers very good penetration (tree canopy, sea water) but has low spatial resolution?
UHF
Which orbit is used for optical sensing?
Sun-synchronous (LEO)
What are the 3 remote sensing imagery classifications?
1) Panchromatic (grayscale) - good spatial rez
2) Multispectral Imaging (MSI) - lower spatial rez
3) Hyperspectral - low spatial rez
What colors (bands) does panchromatic imaging collect?
Blue, gree & red (displays in grayscale)
What band(s) does MSI capture?
Light (including IR) from a narrow range of wavelength across the EM spectrum.
How does hyperspectral collect light?
Hundreds of very narrow bands across the visible & IR spectrum.
Hyperspectral provides _____ discrimination but _____ spatial rez.
High; low
Which type of imagery can distiguish between many kinds of vegetation?
Hyperspectral (Hyperion)
Spatial rez (size & shape) and spectral rez (composition) are _____ proportional.
Inversely
Using gases to determine composition is a function of…
Spectroscopy
Which remote sensing application can determine how much water is in dirt (mud!)?
Hydrology
Which remote sensing app uses temporal rez?
Change detection (red has fled, blue is new)
Which remote sensing app can map the sea floor (trenches, reefs, depth)?
Bathymetry
Which is the only remote sensing band that cannot be used both day and night?
Visible light
To get a combo of spatial & spectral rez requires what technique?
Image fusion
