1. Energy Flow Concept Image Sensor Energy Source
Atmospheric Absorption and Scattering
Reflectance
Absorption
Transmittance
Interpretation and Analysis
Landscape
Information, maps and statistics, for Applications

2. Spectral responses of different materials
Clear Water
Green Vegetation
Turbid Water
Light Soil
Dark Soil

3. Wavelength and Frequency
Units of wavelength:
Nanometers: 1 nm = 10-9 m
Micrometers: 1 μm = 10-6 m
c = λv
where:
λ = wavelength (m)
V = frequency (cycles/second, Hz)
c = speed of light (3x108 m/s)

4. Electromagnetic Spectrum

5. Radiant Flux
Total power of EM radiation emitted from object (or incident upon a surface)
Wavelength dependent upon temperature
Energy also dependent upon temperature

6. Radiation Laws Wien’s Displacement Law
Relationship between the wavelength of radiation emitted and temperature of the object
Where m is the wavelength of maximum emission
Hotter objects have maximum emittance (radiance) at shorter wavelengths

7. Radiation Laws Stefan-Boltzman Law
Radiation emitted from a blackbody is proportional to the fourth power of its absolute temperature
W = σ T4
σ is Stefan-Boltzman constant
x 10-8 (Wm-2 K-4)
T is absolute temperature in Kelvin (K)
Energy emitted from an object is primarily a function of its temperature

10. EM interactions with matter

11. Atmospheric Absorption

12. Atmospheric Absorption

13. Atmospheric Effects
Scattering by suspended particles or large gas molecules redirects electromagnetic energy
Type of scattering depends on atmospheric composition

14. Atmospheric Visibility… a good indictor of atmospheric effects in remote sensing

15. EMR Energy Budget
AKA: Backscatter
or path radiance

16. Remote Sensing Equation
LA = 1/  E  + LP
LA = apparent radiance detected by sensor
 = reflectance
E = solar irradiance
 = atmospheric transmittance
LP = contribution to apparent radiance by atmospheric scattering