Applications of the Electromagnetic Spectrum Bandwidths - Research Paper Example

? Applications of the Electromagnetic Spectrum Bandwidths The Electromagnetic Spectrum of light is the complete sequence of frequencies of electromagnetic radiation emitted by all objects. From those with the shortest wavelengths such as ultraviolet light and x-rays to those with the longest wavelengths like microwaves and radio waves, these various bandwidths of the Electromagnetic Spectrum have several applications including the medical sciences, home management and most of all, in providing data regarding earth system processes, weather and other essential areas. X-rays X-rays are used to determine the structure of all crystals, where “soft” x-rays have long wavelengths and “hard” with shorter wavelengths and relatively higher energies. These energies are utilized to ionize atoms in the atmosphere and destroy chemical bonds. These x-rays are produced by neutron stars or extremely hot objects and a few radioactive sources. Moreover, in the medical field, x-rays are used to treat cancers, and that while soft x-rays are stopped by air, hard x-rays can penetrate deeply into the damaged tissue (“The Electromagnetic Spectrum”). Nevertheless, one distinguishing feature of x-rays in its use in geophysics is that through x-ray images of the sun, one can obtain important clues with regard to solar flares and other physical changes in the sun that can affect space weather and Earth weather. (De Lloyd) Ultraviolet Rays Aside from the practical uses of UV in detecting forged bank notes, hardening certain types of dental filling and sterilization of surgical equipment in hospitals (“Ultra Violet”), this kind of light is also placed on UV telescopes on satellites in order to measure the amount of UV coming from stars, galaxies and the Sun itself. Moreover, astronomers can study stars and galaxies by virtue of the UV light that they give off (“Ultraviolet Waves,” NASA). UV radiation coming from the sun can also produce ionized atomic oxygen, nitrogen and nitrogen oxide gases (“Ultraviolet Rays”). UV has enough energy in its photon, which is even more than enough to ionize an atom. UV therefore effects the binding of essential atoms. (“The Electromagnetic Spectrum”) UV light is also used in the portable spectrometer, which measures spectral radiance, spectral reflectivity and spectral irradiance of various surfaces. In the portable spectrometer, UV light is used with all the visible light as well as Near Infrared light. (“Observing the Earth”) Visible Rays Aside from its most practical purpose, which is to allow the eyes to view the world, visible light, it is also used for communication, specifically in the “transport [of] huge volumes of information over very large distances” by means of internal reflection in optical fibers (Emery). Moreover, visible red, green and blue false color assignments are used to reflect radiant energy emitted by the Earth’s surface and atmosphere. Specifically, visible blue light from 0.45 to 0.52 µm is used for mapping details of how deep water-covered areas are, considering that it is the most absorbed wavelength of water. Visible blue light is also utilized by the Landsat TM satellite sensor as spectral band 1 (“An Introduction to Remote Sensing,” Yale University). Landsat TM is a satellite sensor that detects changes in the biosphere such as wildfires, deforestation and natural calamities and such data on these changes will be provided to concerned institutions including the government, the education sector as well as commercial and industrial communities. (“Landsat Multispectral Scanner”) Visual green light, on the other hand, from 0.50 to 0.60 µm is also used to map out depth or the presence of sediment in bodies of water. Roads and buildings can also be detected by this particular bandwidth. In satellite sensors, visible green light is used as spectral band 1 in the Landsat MSS, as band 2 in Landsat TM, and as another band in Landsat ETM+. These Landsat satellite sensors aid in the detection of biosphere changes ranging from moisture content of the soil to natural disasters. (“Landsat Multispectral Scanner”) Lastly, visual red light from 0.60 to 0.70 µm is very useful in detecting the presence of plant species as well as the presence of soil and the location of geologic boundaries. Visual or visible red light is also used as Band 1 of the spectral bands used in the satellite sensor known as Advanced Very High Resolution Radiometer, or AVHRR. The AVHRR uses spectral bands that are utilized for mapping large geographical areas to detect snow, vegetation, floor, dust, wildfire, sandstorm and soil moisture analysis (“An Introduction to Remote Sensing,” Yale University). Visible red light is also used as band 2 in Landsat MSS, band 3 in Landsat TM, and as another spectral band in Landsat ETM+. These aforementioned satellite sensors all function to detect changes on earth including floods, degradation of water sources and wildfires. (“An Introduction to Remote Sensing,” Yale University). Visible light is also used in the portable spectrometers, which measures radiance, reflectivity and irradiance of spectra of light on various surfaces. In the portable spectrometer, visible light is used with UV light and Near Infrared light. Moreover, the Geostationary Operational Environment Satellites, or GOES, whose operations began in 1975, use visible light for its spectral band 1. The visible band in the GOES produces a clear 1 km resolution of images of clouds and those of the Earth’s surface. Still, another use of visible light is in making up the first three spectral bands of the 4-band IKONOS, which is currently “the world’s first commercial, high resolution satellite” (“Observing the Earth”). The first spectral band of the IKONOS utilizes blue visible light in order to map the depth and detail of areas covered with water. It also functions to discriminate between soil and vegetation as well as to map forests and other cultural features of the land. The second spectral band, which uses green visible light, is used to reflect chlorophyll present in healthy vegetation. The third spectral band, which utilizes red visible light, is more accurate as it detects and distinguishes among different species of plants as well as boundaries between soil and other geologic forms. One last recently built satellite, the Japan Earth Resources Satellite or JERS, is an 8-band satellite using green visible light for band 1 and red for band 2. Green light is, as usual, used to detect healthy vegetation, and red light is used to precisely distinguish among the different plant species. (“Observing the Earth”) Other uses of visible light include the chemical reactions of vision and photosynthesis and may trigger the diodes in solar cells to effect a potential difference. (“The Electromagnetic Spectrum”). In short, without visible light one can definitely not see, plants would not be able to undergo photosynthesis and make glucose, and solar cells would not be able to work. Infrared Rays Infrared waves are used mainly for short-range communications such as between mobile phones (“Infra Red”). Moreover, as the Earth, the Sun and other stars and galaxies also emit infrared light, this kind of light is utilized by satellites such as GOES 6 and Landsat 7. These satellites use special sensors that record data on how much infrared light is reflected or emitted by the surface of the Earth. If infrared is detected from stars, galaxies, large clouds of dust in space and planets like the Earth, it will be “easier to distinguish clouds from land in the visible range” (“Infrared Waves,” NASA). The purpose of this is to study cloud structure and to determine which clouds are relatively warmer and which are relatively cooler. Generally, lighter clouds are cooler and darker clouds are warmer. (“Infrared Waves,” NASA) Specifically, Near Infrared light, measuring from 0.70 to 0.80 µm, is used for detecting vegetation biomass as well as soil-crop and land-water boundaries. The second Near Infrared light, from 0.80 to 1.10 µm, is normally used for discriminating between the types of vegetation, detection of haze and water-land boundaries. The first of the three Mid-Infrared light bandwidths, measuring 1.55 to 1.74 µm, is extremely useful in distinguishing snow, ice and clouds, as well as the state of vegetation. The second Mid-Infrared light bandwidth, measuring 2.08 to 2.35 µm, is useful in mapping various geologic formations as well as soil boundaries and the moisture content of both plant and soil. The third Mid-Infrared light bandwidth, which has a length from 3.55 to 3.93 µm, can detect sunlight and radiation emitted from the Earth. It is also useful in discriminating between snow and ice as well as in the detection of forest fires. Finally, Thermal Infrared light, ranging from 10.40 to 12.50 µm, is useful for detection of crop stress, heat intensity, thermal pollution, insecticide applications, geothermal mapping and measurements of water surface temperature (“An Introduction to Remote Sensing,” Yale University). Near Infrared light is also used in the portable spectrometer, which measures radiance, irradiance and reflectivity of various surfaces. In the portable spectrometer, Near Infrared light is used with all the visible light as well as Near Infrared light. (“Observing the Earth”) Infrared light is also used as spectral bands of various satellite sensors. For the Advanced Very High Resolution Radiometer, or AVHRR, spectral band 2 is Near Infrared, band 3 is Infrared, and bands 3 and 4 are Thermal Infrared. These spectral bands are utilized by the AVHRR for detecting vegetation, and various geophysical phenomena such as snow, dust, wildfire and sandstorms. Moreover, infrared light is used in the Landsat Multi-Spectral Scanner satellite sensor. Spectral bands 3 and 4 of the Landsat MSS utilizes Near Infrared light to provide information regarding anthropogenic and natural changes on Earth from several months to 20 years. These changes may include deforestation, agricultural development, natural disasters, desertification, urbanization and degradation of water resources. Data on these changes are essential to government, industrial, civilian, commercial and educational communities in the United States and throughout the world (“Landsat Multispectral Scanner”). Another satellite sensor, known as the Landsat TM, performs the same functions as the Landsat MSS. For this sensor, Near Infrared light serves as its spectral band 4, Mid-Infrared serves as band 5 and 7, and Thermal Infrared serves as band 6. The Thermal Infrared band is also used in the Landsat Enhanced Thematic Mapper Plus, or Landsat ETM+, for exactly the same purpose as Landsat MSS. (“An Introduction to Remote Sensing,” Yale University) The Geostationary Operational Environmental Satellites, or GOES, also make use of Infrared light in their spectral bands. Specifically, Mid-Infrared light is used for band 2, and Thermal Infrared for bands 4 and 5. Band 2 is useful in discriminating among snow, water and ice, measuring sea surface temperature at night, and monitoring hot spots such as volcanoes and forest fires. Band 4, on the other hand, provides data for temperatures of cloud tops and sea surface during both day and night. The third band using Infrared light, band 5, which works in conjunction with band 4, provides data on water vapor absorption as well as data on sea surface and low-level moisture. Aside from the latest series of GOES, another newly launched satellite is the IKONOS satellite, which is known as “the world’s first commercial, high-resolution satellite” (“Observing the Earth”). Although the first three spectral bands of the IKONOS utilize visible light, band 4 uses Near Infrared light and is useful in detecting variations in vegetation biomass as well as emphasizing boundaries between soil and crop as well as between land and water. Aside from the GOES series and the IKONOS, the Japan Earth Resources Satellite of JERS also utilizes mostly Infrared light for 6 of its 8 spectral bands. Near Infrared light for bands 3 and 4 is used for the detection of plant biomass. Mid-Infrared light is used for bands 5, 6, 7 and 8, band 5 is normally used to detect plant water content, while the other three bands are used tomap and detect particular geologic formations as well as produce distinct images of plant and soil moisture. (“Observing the Earth”) Other applications of Infrared light include the use of Infrared or IR binoculars to detect and locate mammals which are usually warmer than the environment. (“The Electromagnetic Spectrum”) Microwave Rays Aside from their application in food preparation and heating, microwaves are used in telecommunications especially in mobile phones as these waves can be generated using a small antenna and a small phone. Another use of microwaves is in a radar as this particular equipment sends out bursts of microwaves that detect echoes bouncing back from the objects these waves hit. The length of time the echoes are received are also used to determine the distance of the object detected by the radar (“Microwaves”). These microwaves can also be used in remote sensing and can penetrate fog, rain and clouds. (“An Introduction to Remote Sensing,” Yale University) Radio Waves Radio waves are extensively used for all kinds of communication, aircraft navigation, guided missile communication, radar and television transmission (Emery). Specifically, the Ku band at 13.6 GHz is the most commonly-used frequency for communication and the Ka band at 35 GHz is used to better observe ice, rain, land masses, coastal zones, and wave heights (“Radar Altimetry”). Moreover, radio waves are used to create images, especially those radio waves with short lengths and are transmitted from an airplane antenna or satellite. One advantage of radio waves is that they can form an image of the ground despite the darkness of the night and the thickness of clouds. (De Lloyd) Works Cited “An Introduction to Remote Sensing and GIS.” Yale University, n.d. Web. 23 Apr 2011. De Lloyd, Dhanial. “The Electromagnetic Spectrum of Radiation.” The University of the West Indies, 2000. Web. 25 Apr 2011. Emery, Robert. “The World Communicates.” Catholic Schools Diocese of Maitland-Newcastle, 2002. Web. 25 Apr 2011. “Infra Red.” Andy Darvill’s Science Site, n.d. Web. 25 Apr 2011. “Infrared Waves.” National Aeronautics and Space Administration, 2007. Web. 25 Apr 2011. “Landsat Multispectral Scanner (MSS) and Thematic Mapper (TM).” University of Minnesota, 8 Apr 2011. Web. 26 Apr 2011. “Microwaves.” Andy Darvill’s Science Site, n.d. Web. 23 Apr 2011. “Observing the Earth from Space.” Yale University, n.d. Web. 23 Apr 2011. “Radar Altimetry Tutorial.” European Space Agency, 2011. Web. 24 Apr 2011. “The Electromagnetic Spectrum.” The University of New South Wales, n.d. Web. 27 Apr 2011. “Ultra Violet.” Andy Darvill’s Science Site, n.d. Web. 23 Apr 2011. “Ultraviolet Rays.” Oracle ThinkQuest, n.d. Web. 24 Apr 2011. “Ultraviolet Waves.” National Aeronautics and Space Administration, 2007. Web. 25 Apr 2011. Read More