1,721,073 research outputs found
Scanning Polarimetric Imaging Radiometer: Microwave Imaging System and Image Merging with IR and Optical Data
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Radiometric Method for Emissivity Retrieval in High Reflective Materials
Full text linkHigh reflective materials in the microwave region play a very important role in the realization of antenna reflectors for a broad range of applications, including radiometry. These reflectors have a characteristic emissivity which needs to be characterized accurately in order to perform a correct radiometric calibration of the instrument. Such a characterization can be performed by using open resonators, waveguide cavities or by radiometric measurements. The latter consists of comparative radiometric observations of absorbers, reference mirrors and the sample under test, or using the cold sky radiation as a direct reference source. While the first two mentioned techniques are suitable for the characterization of metal plates and mirrors, the latter has the advantages to be also applicable to soft materials. This paper describes how, through this radiometric techniques, it is possible to characterize the emissivity of the sample relative to a reference mirror and how to characterize the absolute emissivity of the latter by performing measurements at different incident angles. The results presented in this paper are based on our investigations on emissivity of a multilayer insulation material (MLI) for space mission, at the frequencies of 22 and 90 GHz
Monitoring of Middle Atmospheric Water Vapour
No full textThe Institute of Applied Physics (IAP) at the University of Bern has operated its 22 GHz microwave radiometer MIAWARA for remote sensing of water vapor in the middle atmosphere since April 2002. In 2006 it was installed at the Zimmerwald Observatory near Bern and has since provided long-term observations of this essential climate variable in the stratosphere and lower mesosphere in the altitude range of approximately 20–70 km
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