Three-dimensional Lidar for Wind Shear Detection and Early Warning in Civil Aviation Airport

2019 ◽  
Vol 48 (5) ◽  
pp. 512001
Author(s):  
冯力天 FENG Li-tian ◽  
周杰 ZHOU Jie ◽  
范琪 FAN Qi ◽  
陈永雄 CHEN Yong-xiong ◽  
刘志平 LIU Zhi-ping ◽  
...  
Keyword(s):  
Early Warning ◽  
Wind Shear ◽  
Three Dimensional ◽  
Civil Aviation

scholarly journals An account of low level wind shear over Chennai airport - Part II : Turbulence and eddy dissipation

MAUSAM ◽  
2021 ◽  
Vol 60 (3) ◽  
pp. 325-342
Author(s):  
R. SURESH
Keyword(s):  
Wind Shear ◽  
Three Dimensional ◽  
Civil Aviation ◽  
Atmospheric Conditions ◽  
Velocity Data ◽  
Mean Power ◽  
General Belief ◽  
Low Level ◽  
International Civil Aviation Organisation ◽  
Radial Velocity Data

In-flight reports on Low Level Wind Shear (LLWS) received from aircrafts are used to issue wind shear alerts for all subsequent landing aircrafts as per standing guidelines of International Civil Aviation Organisation (ICAO). In this paper, winds reported by aircrafts at 1000 and 1800 ft. are used to validate the wind estimated from DWR measured radial wind data employing standard algorithms. Turbulence indices and parameters have been computed independently using conventional (RS/RW) upper air data, aircraft measured winds and DWR estimated winds and compared these with wind shear induced turbulence reported by aircrews. Mean power law (wind escalation law) profiles in the boundary layer have been arrived at for unstable and stable atmospheric conditions.                   Three dimensional shear (3DS) upto 600 m a.g.l. has been worked out from DWR measured radial velocity data and compared with wind shear computed from RS/RW and aircraft measured winds and DWR estimated winds. It is found that 3DS values of more than 16 * 10-3 s-1 predict well the occurrence of moderate turbulence. Contrary to the general belief that wind shear is a short lived phenomenon which may last for a few minutes only, it has been observed that incidences of LLWS and induced moderate turbulence lasting more than 10 hrs are not at all uncommon over Chennai aircraft.

The Research of Collision Detection Based on OBB in Vega Prime

2012 ◽  
Vol 220-223 ◽  
pp. 2803-2808
Author(s):  
Xiao Ping Wang ◽  
Xiu Cheng Dong
Keyword(s):  
Early Warning ◽  
Collision Detection ◽  
Line Segment ◽  
Three Dimensional ◽  
Trend Line ◽  
Three Dimensional Objects ◽  
Bounding Box ◽  
Object Based ◽  
Early Warning Mechanism ◽  
Dimensional Object

Collision detection in Vega Prime is based on the simple line segment, and collision detection based on bounding box is not realized. By studying the composition of three-dimensional object based on Oriented Bounding Box (OBB), we define a collision detection class, which inherits from vpIsector. After finding out all vertices of geometry in object, we connect these vertices one by one and constitute a tend line. The trend line constitutes our bounding box based on OBB. Now, our collision detection is based on three-dimensional objects, but not the simple line segment. At the same time, we can control the efficiency of collision detection by increasing or decreasing the number of collision lines on the actual demand. Additionally, on this basis, we have made the further application. By adjusting parameter, we can get a bounding box with early warning mechanism or collision tolerance.

Retrieved Thermodynamic Structure of Hurricane Rita (2005) from Airborne Multi-Doppler Radar Data

2021 ◽  
Author(s):  
Annette M. Boehm ◽  
Michael M. Bell
Keyword(s):  
Wind Shear ◽  
Doppler Radar ◽  
Three Dimensional ◽  
Vertical Wind Shear ◽  
Vertical Motion ◽  
Radar Data ◽  
Vertical Wind ◽  
Vertical Acceleration ◽  
Hurricane Rita ◽  
Doppler Radar Data

AbstractThe newly developed SAMURAI-TR is used to estimate three-dimensional temperature and pressure perturbations in Hurricane Rita on 23 September 2005 from multi-Doppler radar data during the RAINEX field campaign. These are believed to be the first fully three-dimensional gridded thermodynamic observations from a TC. Rita was a major hurricane at this time and was affected by 13 m s−1 deep-layer vertical wind shear. Analysis of the contributions of the kinematic and retrieved thermodynamic fields to different azimuthal wavenumbers suggests the interpretation of eyewall convective forcing within a three-level framework of balanced, quasi-balanced, and unbalanced motions. The axisymmetric, wavenumber-0 structure was approximately in thermal-wind balance, resulting in a large pressure drop and temperature increase toward the center. The wavenumber-1 structure was determined by the interaction of the storm with environmental vertical wind shear resulting in a quasi-balance between shear and shear-induced kinematic and thermo-dynamic perturbations. The observed wavenumber-1 thermodynamic asymmetries corroborate results of previous studies on the response of a vortex tilted by shear, and add new evidence that the vertical motion is nearly hydrostatic on the wavenumber-1 scale. Higher-order wavenumbers were associated with unbalanced motions and convective cells within the eyewall. The unbalanced vertical acceleration was positively correlated with buoyant forcing from thermal perturbations and negatively correlated with perturbation pressure gradients relative to the balanced vortex.

scholarly journals EGNOS Based APV Procedures Development Possibilities In The South-Eastern Part Of Poland

2014 ◽  
Vol 21 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Wojciech Z. Kaleta
Keyword(s):  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Satellite System ◽  
Civil Aviation ◽  
The South ◽  
South Eastern ◽  
System Integrity ◽  
New Instrument ◽  
Global Navigation Satellite ◽  
First Time

AbstractOn 14th and 15th March 2011 for the first time approach with vertical guidance (APV-I) was conducted on Polish territory in Katowice, Kraków and Mielec. This was the milestone for GNSS (Global Navigation Satellite System) and Area Navigation (RNAV) use as a new instrument approach chance for NPA (Non-Precision Approach) and PA (Precision Approach) in Poland. The paper presents the experiment study of EGNOS SIS (Signal in Space) due to APV (Approach with Vertical Guidance) procedures development possibilities in the south-eastern part of Poland. Researches were conducted from January 2014 till June 2014 in three Polish cities: Warszawa, Kraków and Rzeszów. EGNOS as SBAS (Satellite Based Augmentation System) in according with ICAO's Annex 10 has to meet restrictive requirements for three dimensional accuracy, system integrity, availability and continuity of SIS. Because of ECAC (European Civil Aviation Conference) states to EGNOS coverage in the eastern part of Europe, location of mention above stations, shows real usefulness for SIS tests and evaluation of the results [EUROCONTROL, 2008].

Suppressing van der Waals driven rupture through shear

2010 ◽  
Vol 661 ◽  
pp. 522-539 ◽  
Author(s):  
M. J. DAVIS ◽  
M. B. GRATTON ◽  
S. H. DAVIS
Keyword(s):  
Free Surface ◽  
Wind Shear ◽  
Capillary Wave ◽  
Van Der Waals ◽  
Three Dimensional ◽  
Angular Speed ◽  
Critical Value ◽  
Finite Amplitude ◽  
Two Dimensions ◽  
Sivashinsky Equation

An ultra-thin viscous film on a substrate is susceptible to rupture instabilities driven by van der Waals attractions. When a unidirectional ‘wind’ shear τ is applied to the free surface, the rupture instability in two dimensions is suppressed when τ exceeds a critical value τc and is replaced by a permanent finite-amplitude structure, an intermolecular-capillary wave, that travels at approximately the speed of the surface. For small amplitudes, the wave is governed by the Kuramoto–Sivashinsky equation. If three-dimensional disturbances are allowed, the shear is decoupled from disturbances perpendicular to the flow, and line rupture would occur. In this case, replacing the unidirectional shear with a shear whose direction rotates with angular speed, , suppresses the rupture if τ ≳ 2τc. For the most dangerous wavenumber, τc ≈ 10−2 dyn cm−2 at ≈ 1 rad s−1 for a film with physical properties similar to water at a thickness of 100 nm.

The Key Technology of the Application of MultiGen Creator / Vega Prime in Visual Simulation System of Civil Aviation Airport

2012 ◽  
Vol 263-266 ◽  
pp. 1796-1799 ◽  
Author(s):  
Wei Wei Song
Keyword(s):  
Traffic Control ◽  
Three Dimensional ◽  
Simulation System ◽  
Air Traffic ◽  
Civil Aviation ◽  
Visual Simulation ◽  
Operating Efficiency ◽  
Working Pressure ◽  
Air Traffic Controller ◽  
Multigen Creator

Visual simulation is the most important manifestation of virtual reality technology. Take a civil aviation airport as an example of visual simulation, based on the real-time, interactivity and realism of visual simulation system, we discuss Creator 3.0 in building three-dimensional scene of the civilian airport, and the development of visual simulation system based on Vega Prime. The simulation results show that it provides the basis for the safe and reliable in air traffic control, reducing the working pressure of the air traffic controller, improving the operating efficiency of the air traffic, and increasing the traffic flow of air and surface.

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