Micro-Doppler analysis of rotary-wing air vehicles using pulsed-Doppler radar

2018 ◽  
Author(s):  
Bahadir Aybar ◽  
Ali Ozgur Yilmaz
Keyword(s):  
Doppler Radar ◽  
Pulsed Doppler ◽  
Rotary Wing ◽  
Doppler Analysis ◽  
Air Vehicles

Clinical evaluation of a new anti-aliasing technique for ultrasound pulsed Doppler analysis

1989 ◽  
Vol 15 (8) ◽  
pp. 749-756 ◽  
Author(s):  
P. Tortoli ◽  
F. Valgimigli ◽  
G. Guidi ◽  
P. Pignoli
Keyword(s):  
Clinical Evaluation ◽  
Pulsed Doppler ◽  
Doppler Analysis

Design Optimization of Rotary-Wing Micro Air Vehicles

2006 ◽  
Vol 220 (6) ◽  
pp. 865-873 ◽  
Author(s):  
T T H Ng ◽  
G S B Leng
Keyword(s):  
Design Optimization ◽  
Design Methodology ◽  
Optimization Problem ◽  
Micro Air Vehicles ◽  
Robust Performance ◽  
And Control ◽  
The Given ◽  
Rotary Wing ◽  
Air Vehicles

In this paper, a new design methodology is introduced to automate the configuration layout design and geometric sizing of rotary-wing micro air vehicles (MAV). The objective of this design-optimization problem is to organize a given set of components and payloads such that the resulting flight vehicle has the most compact overall size and still fulfils the given physical and control constraints. Genetic algorithm (GA) is chosen as the optimization engine because of its proven robust performance. A detailed discussion is presented to explain how the rotary-wing MAV design problem can be formulated as a GA optimization problem. From the case study performed, it is demonstrated that the proposed methodology is able to achieve the design goal.

scholarly journals Comparison of Single Doppler and Multiple Doppler Wind Retrievals in Hurricane Matthew (2016)

2020 ◽  
Author(s):  
Ting-Yu Cha ◽  
Michael M. Bell
Keyword(s):  
Tropical Cyclone ◽  
Wind Field ◽  
Doppler Radar ◽  
Three Dimensional ◽  
Airborne Radar ◽  
Limited Information ◽  
Fourier Decomposition ◽  
Wind Retrieval ◽  
Advantages And Disadvantages ◽  
Doppler Analysis

Abstract. Hurricane Matthew (2016) was observed by the NEXRAD KAMX polarimetric radar and NOAA P-3 airborne radar near the coast of the southeastern United States for several hours, providing a novel opportunity to evaluate and compare single and multiple Doppler wind retrieval techniques for tropical cyclone flows. The generalized velocity track display (GVTD) technique can retrieve a subset of the wind field from a single ground-based Doppler radar under the assumption of nearly axisymmetric rotational wind, but is shown to have errors from aliasing of unresolved wind components. An improved technique that mitigates errors due to storm motion is derived in this study, although some spatial aliasing remains due to limited information content from the single Doppler measurements. A spline-based variational wind retrieval technique called SAMURAI can retrieve the full three-dimensional wind field from airborne radar fore-aft pseudo-dual Doppler scanning, but is shown to have errors due to temporal aliasing from the non-simultaneous Doppler measurements. A comparison between the two techniques shows that the axisymmetric tangential winds are generally comparable between the two techniques after the improvements to GVTD retrievals. Fourier decomposition of asymmetric kinematic and convective structure shows more discrepancies due to spatial and temporal aliasing in the retrievals. The advantages and disadvantages of each technique for studying tropical cyclone structure are discussed, and suggest that complementary information can be retrieved from both single and multiple Doppler retrievals. Future improvements to the asymmetric flow assumptions in single Doppler analysis and steady-state assumptions in pseudo-dual Doppler analysis are required to reconcile differences in retrieved tropical cyclone structure.

Energy requirements for the flight of micro air vehicles

2001 ◽  
Vol 105 (1045) ◽  
pp. 135-149 ◽  
Author(s):  
M. I. Woods ◽  
J. F. Henderson ◽  
G. D. Lock
Keyword(s):  
Optimal Solution ◽  
Micro Air Vehicles ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
The Public ◽  
Flight Mode ◽  
Lift And Drag ◽  
Lift And Drag Coefficient ◽  
Rotary Wing ◽  
Air Vehicles

Abstract This paper describes power requirements for micro air vehicles, flying in the Reynolds number regime of -lO*. Three flight modes have been researched: fixed wing, rotary wing and flapping wing. For each mode, the literature in the public domain has been reviewed to obtain appropriate lift and drag coefficient data at these low Reynolds numbers. Energy and power requirements for the three flight modes have been calculated and an optimisation procedure has been utilised to evaluate the most efficient flight mode and configuration for a variety of specified missions. The effect of wind-speed on the optimal solution has been examined. It has been discovered that when there is no hover requirement, fixed wing flight is always most energy efficient for the micro air vehicle. However, if there is a hover requirement, the suitability of flapping or rotary wing flight is dependent on the mission profile and ambient windspeed.

Sign in / Sign up

Export Citation Format

Share Document