Sökning: "sub-mm"

Visar resultat 1 - 5 av 16 avhandlingar innehållade ordet sub-mm.

1. 1. Microwave Radiometric Observations of the Middle Atmosphere: Simulations and Inversions

   Författare :Patrick Eriksson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atmospheric radiative transfer; middle atmosphere; sub-mm; data inversion; profile retrieval; microwaves; limb sounding; ozone; remote sensing;

   Sammanfattning : Two well-known examples of global environmental problems are the ozone depletion and the enhanced greenhouse effect. The importance and the complexity of these questions generate a demand for improved atmospheric observations, and microwave radiometry is an approach which is increasingly important for measurements of the middle atmosphere (10-100 km). LÄS MER

3. 2. MgB2 hot-electron bolometer mixers for sub-mm wave astronomy

   Författare :Evgenii Novoselov; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; hot-electron bolometer; gain bandwidth; noise bandwidth; thin film; electron-phonon interaction; noise temperature; THz detector; conversion gain; mixer; magnesium diboride; superconductor;

   Sammanfattning : Spectroscopy and photometry in the terahertz (THz) range of remote space objects allows for a study of their chemical composition, because this range covers rotational lines from simple molecules and electron transition lines from atoms and ions. Due to high spectral resolution, THz heterodyne receivers al- low for studying dynamical properties of space objects manifested in doppler-shifted emission lines. LÄS MER

4. 3. Satellite microwave measurements of cloud ice properties

   Författare :Bengt Rydberg; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; sub-mm; cirrus; upper troposphere; Odin; remote sensing; CloudSat; data retrieval;

   Sammanfattning : Upper tropospheric cloud ice and water vapour are two intimately connected components of the atmosphere, that influence the Earth's energy budget. The response of these components to a warming climate is not well understood. LÄS MER

5. 4. Lumped arrays of Josephson junction oscillators

   Författare :Jonas Edstam; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lumped array; Josephson oscillator; subharmonic generation; tunnel junction; inductive shunt; local oscillator; Josephson junction; LC-resonance; submicron junction; sub-mm wave; Nb PbBi junction; SIS junction; window junction;

   Sammanfattning : .... LÄS MER

7. 5. Satellite microwave measurements of ice cloud properties

   Författare :Bengt Rydberg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cirrus; radiative transfer; CIWSIR; microphysical properties; inversions; Odin;

   Sammanfattning : Ice clouds play an important role in Earth's radiation balance and climate because they reflect incoming sunlight and trap outgoing infrared radiation. There is still an uncertainty about how ice clouds will respond to the effects of global warming. Many climate models use prognostic cloud mass schemes to represent cloud feedbacks. LÄS MER