Radar remote sensing of the lower atmosphere

مرکز و کتابخانه مطالعات اسلامی به زبان های اروپایی

منو

" Radar remote sensing of the lower atmosphere "
Karimian, Ali

Document Type	:	Latin Dissertation
Language of Document	:	English
Record Number	:	904089
Doc. No	:	TL3xz039vc
Main Entry	:	Karimian, Ali
Title & Author	:	Radar remote sensing of the lower atmosphere\ Karimian, Ali
College	:	UC San Diego
Date	:	2012
student score	:	2012
Abstract	:	Non-standard radio wave propagation in the atmosphere is caused by anomalous changes of the atmospheric refractivity index. These changes, if not accounted for, can cause major problems in detection of the location of flying targets. Direct sensing of the atmospheric refractivity index by measuring humidity and temperature has been common practice in past. Refractivity from clutter (RFC) was developed in recent years to complement traditional ways of measuring the refractivity profile in maritime environments. The ability to track the refractivity profile in time and space, together with a lower cost and convenience of operations have been the promising factors that brought RFC under consideration. Presented is an overview of the basic concepts, research and achievements in the field of RFC. A multiple angle clutter model is derived that is constructed by angular spectral estimation on the propagating power. This model is shown to perform better than conventional clutter models in remote sensing applications. Examples are either based on synthetically generated radar clutter or a set of S-band radar measurements from Wallops Island, 1998. Finally, an approach for fusing RFC output with evaporation duct characterization based on ensemble forecasts from a numerical weather prediction (NWP) model is examined. Relative humidity at a reference height and air-sea temperature difference (ASTD) are identified as state variables. Probability densities of atmospheric parameters and propagation factor obtained from an NWP ensemble, RFC, and joint inversions are compared. It is demonstrated that characterization of the near surface atmosphere by combining RFC and NWP reduces the estimation uncertainty of the refractivity index structure in an evaporation duct using either method alone
Added Entry	:	UC San Diego