903 research outputs found
Empirical Modeling of Ducting Effects on a Mobile Microwave Link Over a Sea Surface
In this paper, signal enhancement due to the ducts over a sea surface is experimentally investigated and modeled. The investigation is carried out through the study of air-to-ground mobile microwave links over a tropical ocean with low airborne altitudes (0.37 - 1.83 km) at C band (5.7 GHz). The distance-dependence of the ducting induced enhancement (with reference to the free-space propagation) is linearly modeled, and the physical variations of the ducts are found to be Gaussian distributed. Empirical ducting coefficients and parameters for the Gaussian function are estimated and provided for the prediction of the distance-dependent signal enhancement due to the ducts in similar scenarios
Detecting Rainfall Onset Using Sky Images
Ground-based sky cameras (popularly known as Whole Sky Imagers) are
increasingly used now-a-days for continuous monitoring of the atmosphere. These
imagers have higher temporal and spatial resolutions compared to conventional
satellite images. In this paper, we use ground-based sky cameras to detect the
onset of rainfall. These images contain additional information about cloud
coverage and movement and are therefore useful for accurate rainfall nowcast.
We validate our results using rain gauge measurement recordings and achieve an
accuracy of 89% for correct detection of rainfall onset.Comment: Accepted in Proc. TENCON 2016 - 2016 IEEE Region 10 Conferenc
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