04-12-2012, 11:40 AM
SEMINAR REPORT ON THERMAL IMAGING
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ABSTRACT
With the general public becoming aware of thermal imaging and infrared technology, medicine and science have been able to flourish in aiding those who are sick and exploring the unknown. MRIs, CT and PET scans have given way to thermal imagery, allowing even more detail to be seen by doctors to better facilitate cures and treatments. Institutions such as NASA can use thermal imagery to locate fires, plot out the geography of a planet or photograph heavenly bodies.
The military originally developed thermal imaging so that soldiers can easier find combatant troops in the dark, allowing for less casualties in war and skirmishes. From the 1950s through the '70s and into the 21st century, advancements have been made in the use of goggles, cameras and hand-held devices to allow military and law enforcement to find people hidden in buildings or brush.
Thermal imaging is used in many industries, including personal safety, military and law enforcement, astronomy, firefighting and medicine. The imagery is produced by using different colors for hot vs. cold, with red being hot and blue being cooler. The sensors will read the heat being emitted from an individual or object and translate that heat into a visual color scheme that the human eye can read.
INTRODUCTION:-
Thermal imaging is borne from thermology, a science that has been in existence for over 3,000 years.
Thermal imaging is used in many industries, including personal safety, military and law enforcement, astronomy, firefighting and medicine.The imagery is produced by using different colors for hot vs. cold, with red being hot and blue being cooler. The sensors will read the heat being emitted from an individual or object and translate that heat into a visual color scheme that the human eye can read.
History of Thermal Imaging:-
Thermal imaging is borne from thermology, a science that has been in existence for over 3,000 years. Thermal imaging is used in many industries, including personal safety, military and law enforcement, astronomy, firefighting and medicine. The imagery is produced by using different colors for hot vs. cold, with red being hot and blue being cooler. The sensors will read the heat being emitted from an individual or object and translate that heat into a visual color scheme that the human eye can read.
The Beginnings of Thermography
Ancient Egyptians used thermology to sense changes in body heat. Hippocrates knew in 400 BC that wherever the body's heat was elevated, disease would be found. Greeks, meanwhile, would put their patients in mud. Whatever part dried faster would be indicative of where the illness was.
The First Equipment
The original form of thermology would last well into the Renaissance Era, until Galileo would discover the thermoscope---a glass tube device that measured temperatures. This would be the grandfather to thermometers. The Celsius measurement system came into being in 1742, and would be revamped by Linnaeus and Wunderlich in the 19th century.
More Modern-Day Advancements
In 1877 Lehmann would discover cholesteric esters, and the use of liquid crystals would begin. Astronomer Sir William Herschel and son John would discover the infrared radiation and the subsequent manner to colorize the images, so that the hottest temperature would be red and the coolest would be blue, giving way to current military equipment.
Military & Law Enforcement
The military originally developed thermal imaging so that soldiers can easier find combatant troops in the dark, allowing for less casualties in war and skirmishes. From the 1950s through the '70s and into the 21st century, advancements have been made in the use of goggles, cameras and hand-held devices to allow military and law enforcement to find people hidden in buildings or brush.
Other Modern-Day Uses
With the general public becoming aware of thermal imaging and infrared technology, medicine and science have been able to flourish in aiding those who are sick and exploring the unknown. MRIs, CT and PET scans have given way to thermal imagery, allowing even more detail to be seen by doctors to better facilitate cures and treatments. Institutions such as NASA can use thermal imagery to locate fires, plot out the geography of a planet or photograph heavenly bodies.
Thermography:
Infrared thermography (IRT), thermal imaging, and thermal video are examples of infrared imaging science. Thermal imaging cameras detect radiation in the infrared range of the electromagnetic spectrum (9–14 µm) and produce images of that radiation, called thermograms.
Since infrared radiation is emitted by all objects above absolute zero according to the black body radiation law, thermography makes it possible to see one's environment with or without visible illumination. The amount of radiation emitted by an object increases with temperature; therefore, thermography allows one to see variations in temperature. When viewed through a thermal imaging camera, warm objects stand out well against cooler backgrounds; humans and other warm-blooded animals become easily visible against the environment, day or night. As a result, thermography is particularly useful to military and other users of surveillance cameras
The appearance and operation of a modern thermographic camera is often similar to a camcorder. Often the live thermogram reveals temperature variations so clearly that a photograph is not necessary for analysis. A recording module is therefore not always built-in.Non-specialized CCD and CMOS sensors have most of their spectral sensitivity in the visible light wavelength range. However by utilizing the "trailing" area of their spectral sensitivity, namely the part of the infrared spectrum called near-infrared (NIR), and by using off-the-shelf CCTV camera it is possible under certain circumstances to obtain true thermal images of objects with temperatures at about 280°C and higher.