Week Four Principles of EMR and how EMR is used to perform RS Energy transfer processes: conduction, convection, radiation Fundamental EMR interactions EMR properties: wavelength (λ), frequency (ν), amplitude (A) Major divisions of the electromagnetic spectrum EMR models Wave: c = λν, Stefan-Boltzmann law, Wien's displacement law Particle: quanta / quantum leap / photon Energy / matter interactions in the atmosphere Refraction Scattering Absorption Reflectance Energy / matter interactions with the terrain Radiation budget equation: radiant flux (Φ) incoming (incident) to terrain must be accounted for Ratios of radiant flux (Φ) for reflectance, absorptance, and transmittance Radiant flux (Φ) density exitance Radiance (L): projected radiant flux density leaving at a specific direction and specific solid angle Energy / matter interactions in the atmosphere - again Energy / matter interactions at the sensor

Gamma rays <0.03 nm X-rays 0.03 – 300 nm UV radiation 0.30 – 0.38 μm Visible light 0.38 – 0.72 μm Infrared Near-infrared 0.72 – 1.30 μm Mid-infrared 1.30 – 3.00 μm Far-infrared 7.00 – 1,000 μm (1 mm) Microwave 1 mm – 30 cm Radio ≥ 30 cm Image from: John R. Jensen. 2007. Introduction to Remote Sensing, 2nd Edition. NJ: Pearson Prentice Hall.

From temp., determine dominant wavelength (λ) using Wien’s displacement law: λmax = k / T From temp., determine total emitted radiation (M) using Stephan-Boltzmann law: Mλ = σ T4 Image from: James B. Campbell. 2007. Introduction to Remote Sensing, 4th Edition. NY: Guilford Publications.

Image from: James B. Campbell. 2007 Image from: James B. Campbell. 2007. Introduction to Remote Sensing, 4th Edition. NY: Guilford Publications.

Image from: John R. Jensen. 2007 Image from: John R. Jensen. 2007. Introduction to Remote Sensing, 2nd Edition. NJ: Pearson Prentice Hall.