Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes (2019) / Chapter Skim
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4 The Advantages of Space-Based Infrared Platforms
4 The Advantages of Space-Based Infrared Platforms
Pages 28-34
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From page 28... ...
Even relatively simple analyses of mid-infrared measurements can return reasonable estimates for NEOs, whereas visible light and near-infrared measurements are severely compromised for size determination. More accurate estimation of sizes using the Near Earth Asteroid Thermal Model (NEATM)
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From page 29... ...
Therefore, an effective space-based survey will have to be designed with a scanning cadence that maximizes the probability that detected objects are observed multiple times at intervals that allow accurate orbits to be established. A space-based telescope operating in the thermal infrared is the approach best capable of giving sufficiently accurate diameters to meet the intent of the George E
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From page 30... ...
Bottke, This function was derived from the NEOWISE data set shown in Team: Update to Determine the Feasibility of in Mainzer et al. and Characterof the Near-Earth Object Science Definition Figure 2-5, with methods discussed Enhancing the Search ization of NEOs, NASA Scienceand further explained in Wright et al.
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From page 31... ...
If follow-up observations determine its spectral type, the mass uncertainty reduces to a factor of 1. Right: An asteroid detected with a ground-based visible observatory has an initial mass uncertainty to within a factor of 20.
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From page 32... ...
Yet the combination of ground-based visual wavelength and infrared 2017 Report of the NEO Science Definition Team | 143 space-based platforms reached the desired completion rate in the shortest time period. The committee, after hearing from scientists and engineers who considered visual wavelength space-based platforms, found no contradiction to numerous previous reports that concluded that an infrared space-based platform dedicated to the survey of NEOs will reach a completeness level of 90 percent for 140-meter-diameter objects sooner than any visual wavelength platform on Earth or in space.
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From page 33... ...
First, it is reasonable to compare performance in the two spectral regions for telescopes of the same size; the costs for both rise so steeply with increasing aperture that only a modest increase in size of a visible light telescope would make it match the cost of an infrared one. Second, since an infrared telescope in space significantly outperforms an in-space visible wavelength telescope, from a cost/ benefit analysis it is unnecessary to consider space-borne visible telescopes in depth.
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From page 34... ...
Visible light and near-infrared measurements are severely compromised for size determination, whereas even relatively simple analyses of mid-infrared measurements can return accurate sizes for NEOs. As a result, a space-based infrared survey is better able to detect and characterize the NEO population to meet the requirements of the George E
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