Lect 6 em spectrum-rs
- 1. 21 October,20 EM Spectrum 1 Lecture 6 - GIS
- 2. Lecture # 6 Dated:21/10/2020 Course(502) Introduction to GIS and RS Electro-Magnetic Spectrum (EMS) or Wavelength regions of electro-magnetic radiation Topic Presented by Rehana Jamal (Geometiciation, GIS Specialist & Geographer) Visiting lecturer studentsdatafiles@gmail.com Faculty of Agricultural Engineering, Arid Agriculture University, Rawalpindi 21 October,20 2 EM Spectrum
- 3. Remote Sensing Technology makes use of the wide range of Electro-Magnetic Spectrum (EMS) from a very short wave "Gamma Ray" to a very long 'Radio Wave'. Definition: “The range of wavelengths for electromagnetic waves--from the very long to the very short--is called the Electromagnetic Spectrum”. 21 October,20 3 Electro-Magnetic Spectrum (EMS) or Wavelength regions of electro-magnetic radiation EM Spectrum Source: https://www.google.com/
- 4. 21 October,20 EM Spectrum 4 Wavelength regions of electro-magnetic radiation have different names ranging from Gamma ray, X-ray, Ultraviolet (UV), Visible light, Infrared (IR) to Radio Wave, in order from the shorter wavelengths to the longer wavelengths. Source: https://www.google.com/
- 5. 21 October,20 EM Spectrum 5 Electro-Magnetic Spectrum (EMS) or Wavelength regions of electro-magnetic radiation
- 6. 21 October,20 EM Spectrum 6 Sporce:https://flexbooks.ck12.org/cbook/ck-12-middle-school-physical- science-flexbook-2.0/section/18.5/primary/lesson/radio-waves-ms-ps Electro-Magnetic Spectrum (EMS) or Wavelength regions of electro-magnetic radiation
- 8. 21 October,20 EM Spectrum 8 Electro-Magnetic Spectrum (EMS) or Wavelength regions of electro-magnetic radiation Direction of light
- 10. 21 October,20 EM Spectrum 10 Electro-magnetic Spectrum
- 11. 21 October,20 11 Radio and TV waves are the longest usable waves, having a wavelength of 1 mile (1.5 kilometer) or more. EM Spectrum Wavelength regions of electro-magnetic radiation Source: https://www.google.com/
- 12. 21 October,20 EM Spectrum 12 Microwaves are used in telecommunication as well as for cooking food.
- 13. 21 October,20 EM Spectrum 13 Source: https://www.google.com/
- 15. 21 October,20 EM Spectrum 15 The region from 0.7 to 0.9 um is known as the photographic or color infrared (CIR). Color InfraRed (CIR) is also referred to as Photo Infrared and falls within the very-near infrared (VNIR) portion of the EM spectrum and forms part of the Reflected Infrared radiation. Reflected IR is distinct from Thermal IR which is radiation in the form of Heat emitted by an object. Color Infra Red Photography
- 16. 21 October,20 EM Spectrum 16 Infrared waves are barely visible. They are the deep red rays you get from a heat lamp. we experience this type of infrared radiation every day in the form of heat! The heat that we feel from sunlight, a fire, a radiator or a warm sidewalk is infrared. Infrared light is even used to heat food sometimes - special lamps that emit thermal infrared waves are often used in fast food restaurants.
- 17. 21 October,20 EM Spectrum 17 Other satellites, like the Infrared Astronomy Satellite (IRAS) look up into space and measure the infrared light coming from things like large clouds of dust and gas, stars, and galaxies. Source:https://www.univie.ac.at/geographie /fachdidaktik/FD/site/external_htmls/image rs.gsfc.nasa.gov/ems/infrared.html Infrared waves in remote sensing Landsat 7 Satellites like GOES 6 and Landsat 7 look at the Earth. Special sensors, like those aboard the Landsat 7 satellite, record data about the amount of infrared light reflected or emitted from the Earth's surface.
- 18. 21 October,20 EM Spectrum 18 Visible light waves are the radiation you can see with your eyes. Their wavelengths are in the range of 1/1000 centimeter. Violet: 0.4 - 0.446 um Blue: 0.446 - 0.500 um Green: 0.500 - 0.578 um Yellow: 0.578 - 0.592 um Orange: 0.592 - 0.620 um Red: 0.620 - 0.7 um Color Infrared: 0.7 - 0.9 um Source: https://www.google.com/
- 19. 21 October,20 EM Spectrum 19 Source: https://www.google.com/ Electromagnetic Spectrum
- 21. 21 October,20 EM Spectrum 21 Ultraviolet rays are what give you sunburn and are used in "black lights" that make object glow. UV is the longest wavelength radiation whose photons are energetic enough to ionize atoms, separating electrons from them, and thus causing chemical reactions. Short wavelength UV and the shorter wavelength radiation above it (X-rays and gamma rays) are called ionizing radiation, and exposure to them can damage living tissue, making them a health hazard. UV can also cause many substances to glow with visible light; this is called fluorescence.
- 22. 21 October,20 EM Spectrum 22 X-rays go through the body and are used for medical purposes. Roentgen's wife's hand Discovered by German physicist Wilhelm Conrad Roentgen in 1895. X-ray of a tooth
- 23. 21 October,20 EM Spectrum 23 Gamma rays are dangerous rays coming from nuclear reactors and atomic bombs. They have the shortest wavelength in the electromagnetic spectrum of about 1/10,000,000 centimeter. These are the most energetic photons, having no defined lower limit to their wavelength. Used to detect rocks and mineral detection Used for bombardment In astronomy they are valuable for studying high- energy objects or regions, however as with X- rays this can only be done with telescopes outside the Earth's atmosphere.
- 24. 21 October,20 24 Electromagnetic spectrum Definition: “The range of wavelengths for electromagnetic waves--from the very long to the very short--is called the Electromagnetic Spectrum”. It includes following wavelengths bands: •Radio and TV waves are the longest usable waves, having a wavelength of 1 mile (1.5 kilometer) or more. •Microwaves are used in telecommunication as well as for cooking food. •Infrared waves are barely visible. They are the deep red rays you get from a heat lamp. •Visible light waves are the radiation you can see with your eyes. Their wavelengths are in the range of 1/1000 centimeter. •Ultraviolet rays are what give you sunburn and are used in "black lights" that make object glow. •X-rays go through the body and are used for medical purposes. •Gamma rays are dangerous rays coming from nuclear reactors and atomic bombs. They have the shortest wavelength in the electromagnetic spectrum of about 1/10,000,000 centimeter. EM Spectrum Summary
- 25. References: • www.google.com • www.wikipedia.com •https://flexbooks.ck12.org/cbook/ck-12-middle-school-physical-science- flexbook-2.0/section/18.5/primary/lesson/radio-waves-ms-ps •https://www.univie.ac.at/geographie/fachdidaktik/FD/site/external_htmls/image rs.gsfc.nasa.gov/ems/infrared.html • Principles of Remote sensing • edited by Lucas L.E. Janssen 21 October,20 25 EM Spectrum