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Full-Text Articles in Physical Sciences and Mathematics
Applying The Optimal Estimation Method For Retrieving Rayleigh-Scatter Lidar Temperatures In The Mesosphere, Jonathan Price, Robert Sica, Ali Jalali
Applying The Optimal Estimation Method For Retrieving Rayleigh-Scatter Lidar Temperatures In The Mesosphere, Jonathan Price, Robert Sica, Ali Jalali
Utah Space Grant Consortium
The Rayleigh-scatter lidar (RSL) system at the Atmospheric Lidar Observatory at Utah State University (ALO-USU) provided a rich database of absolute temperatures throughout the mesosphere from 45 km to above 90 km between 1993 and 2004. Recently, a new method for retrieving absolute temperatures from RSL observations has been developed by a group at the University of Western Ontario (UWO), Canada. The Optimal Estimation Method (OEM) uses machine learning to minimize a cost function by optimizing the temperature parameter in a forward model, in our case the lidar equation, to RSL data. This optimization provides some benefits over the existing …
Extreme Ultraviolet Application Of Carbon Nanotube Structures, Scott Olsen, Richard Vanfleet, David Allred, Steve Turley
Extreme Ultraviolet Application Of Carbon Nanotube Structures, Scott Olsen, Richard Vanfleet, David Allred, Steve Turley
Utah Space Grant Consortium
Windows for extreme ultraviolet (EUV) sources are challenging because of the lack of transparent materials in these wavelengths. Thus, differential pumping apertures and slits are standard. Our group has developed a carbon nanotube (CNT) window consisting of a dense array of square holes. The open area allows a large range of wavelengths to be transmitted, and the high density of holes restricts gas flow, allowing a large pressure difference with differential pumping. The versatility of CNTs allows us to select the peak transmission and pressure ratio (low/high). We have observed pressure ratios of 0.000924, 0.000667, 0.000494, and 0.00118 for air …
Great Salt Lake Halophilic Archaea As A Model For Possible Extant Life On Mars, Alex J. Breda, Michael J. Regan Jr.
Great Salt Lake Halophilic Archaea As A Model For Possible Extant Life On Mars, Alex J. Breda, Michael J. Regan Jr.
Utah Space Grant Consortium
Expansive evaporite mineral deposits and other geological features on Mars are evidence of ancient lacustrine systems before the planet experienced global climatic change (~3.5 Ga). On Mars, as the surface water dried up, hypersaline lakes would have filled the ancient lake basins. On Earth, the Bonneville Basin, in the western United States, tells a similar story in a more recent timeframe. Today, the bottom of this basin is the modern Great Salt Lake (GSL) and the Bonneville Salt Flats. Evaporation of this freshwater lake left large evaporitic mineral deposits that continually supply salt to modern GSL. Parts of the lake …
Radiometric Stability Of The Saber Instrument, Martin G. Mlynczak, Taumi Daniels, Linda A. Hunt, Jia Yue, B. Thomas Marshall, James M. Russell Iii, Ellis E. Remsburg, Joseph Tansock, Roy Esplin, Mark Jensen, Andrew Shumway, Larry Gordley, J. -H. Yee
Radiometric Stability Of The Saber Instrument, Martin G. Mlynczak, Taumi Daniels, Linda A. Hunt, Jia Yue, B. Thomas Marshall, James M. Russell Iii, Ellis E. Remsburg, Joseph Tansock, Roy Esplin, Mark Jensen, Andrew Shumway, Larry Gordley, J. -H. Yee
Space Dynamics Laboratory Publications
The SABER instrument on the National Aeronautics and Space Administration Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics satellite continues to provide a long‐term record of Earth's stratosphere, mesosphere, and lower thermosphere. The SABER data are being used to examine long‐term changes and trends in temperature, water vapor, and carbon dioxide. A tacit, central assumption of these analyses is that the SABER instrument radiometric calibration is not changing with time; that is, the instrument is stable. SABER stratospheric temperatures and those derived from Global Positioning System Radio Occultation measurements are compared to examine SABER's stability. Global Positioning System Radio Occultation measurements are inherently stable …