遙感原理 Wavelength Units Meters (like on last slide and in book, p. 613) More commonly in nanometers (1 nm E 10-9meters) ° Angstroms still used Named for Swedish Astronomer who first named these wavelengths 1 nanometer=10A° 烟台师范学院地理与资源管理学院
遥感原理 烟台师范学院地理与资源管理学院 Wavelength Units • Meters (like on last slide and in book, p. 613) • More commonly in nanometers (1 nm = 10-9meters) • Angstroms still used • Named for Swedish Astronomer who first named these wavelengths • 1 nanometer = 10 Ao
Language of the Energy Cycle The Electromagnetic Spectrum Wavelengthλ Visible Light Energy Radio waves G 300m 30cm 0.Scm 300um 30m 3um 0.um 30nm 3nm 0.3nm 0.03nm 0003nm Wavelengths Speed of light= wavelength(n)x frequency =3x108 m/s in vacuum Wavenumber= 1/ wavelength(cm-) Frequency in ghz(I Hz=sec-) 烟台师范学地理与资源管理学胱
烟台师范学院地理与资源管理学院 • Speed of light = wavelength (l) x frequency = 3 x 108 m/s in vacuum • Wavenumber = 1/ wavelength ( cm-1 ) • Frequency in GHz (1 Hz = sec –1 ) Language of the Energy Cycle: The Electromagnetic Spectrum Wavelength l Energy
Solar Spectrum Shortwave spectrum =visible spectrum. 2500 Sun at 6000K; peak emission at 0.5 u 20 EEEEs° TOA 500 100 。 500 040.81.2162.0242.83.23.64.0 Wavelength (um)
烟台师范学院地理与资源管理学院 Solar Spectrum = Shortwave spectrum =visible spectrum: Sun at 6000K; peak emission at 0.5 mm
Terrestrial Spectrum Longwave Spectrum= Infrared Spectrum= Thermal Spectrum: Sahara Desert on Nimbus 4 Satellite 0.20 Theoretical planck curves 0/6 Earth -300K 300K 0.12 Npeak emission -15 um 0.08 20o 225 75 31200H④ f500 2000 Wavenumber (cm"lI f25 Wavelength (um)
烟台师范学院地理与资源管理学院 CO2 O3 H2O Terrestrial Spectrum = Longwave Spectrum = Infrared Spectrum = Thermal Spectrum: Sahara Desert on Nimbus 4 Satellite Theoretical Planck curves: Earth ~300K, peak emission ~15 mm
Earth Spectrum 250O 200 Incoming from Sun: E= High energy, 500 Sur foce short wavelength 00 500 40.5F 3.2 Wavelength‘u》 020 Outgoing from Earth 300K Low energy 275 Long wavelength 0.4 225 75 f50 2002000 Wavenumber (cm"') a 50 oum wavelength (um)
烟台师范学院地理与资源管理学院 Earth Spectrum Incoming from Sun: High energy, short wavelength Outgoing from Earth Low energy Long wavelength 0.5 mm 20 mm 10 mm