Coherent Laser Radar and the Problem of Aircraft Wake Vortices

Constant, G.; Foord, R.; Forrester, Paul; Vaughan, J. M.

doi:10.1080/09500349414552021

Cited by 30 publications

(9 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This might calculate, for example, the peak or centroid value of the Doppler peak. Target • Characterization and tracking of aircraft wake vortices [7,8] • Monitoring of gaseous species (DIAL, or differential absorption lidar).…”

Section: Figure 1 Generic Coherent Laser Radar (Clr) Systemmentioning

confidence: 99%

Lidar for Turbine Control: March 1, 2005 - November 30, 2005

Harris¹,

Hand²,

Wright³

2006

View full text Add to dashboard Cite

Section: Figure 1 Generic Coherent Laser Radar (Clr) Systemmentioning

confidence: 99%

Lidar for Turbine Control: March 1, 2005 - November 30, 2005

Harris¹,

Hand²,

Wright³

2006

View full text Add to dashboard Cite

“…Initial results for measuring wake vortex position and circulation strength have been encouraging (e.g., Thomson 1994, 1997;Constant et al 1994, Köpp 1994Hannon and Henderson 1995;Brockman et al 1999;Darracq et al 2000;Keane et al 2002;Harris et al 2002;Holzäpfel et al 2003;Köpp et al 2004a,b). One Doppler lidar scanning strategy already used in field trials is to point the lidar beam perpendicular to the flight path as shown in Fig.…”

Section: Introductionmentioning

confidence: 93%

“…Although the lidar detection technique seems to produce very robust results Thomson 1994, 1997;Constant et al 1994;Köpp 1994;Hannon and Henderson 1995;Brockman et al 1999;Holzäpfel 2003;Köpp et al 2004a,b), verifying the accuracy of the measurements is difficult in an operational setting since there are very few other instruments capable of measuring the vortex position and strength to the accuracies obtainable with lidars. Two independent lidar measurements of the same vortices have been attempted, but assumptions are required to determine the error characteristics of each individual measurement.…”

Section: Introductionmentioning

confidence: 95%

“…From this perspective, an attractive instrument for wake vortex detection is the Doppler lidar. Earlier wake vortex detection strategies used a continuous wave (CW) focused Doppler lidar because of the high spatial resolution possible (Constant et al 1994;Harris et al 2002;Köpp et al 2004b). However, the maximum detection range is limited to a few hundred meters (Köpp et al 2004a).…”

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Maximum Likelihood Estimates of Vortex Parameters from Simulated Coherent Doppler Lidar Data

Frehlich

Sharman

2005

Journal of Atmospheric and Oceanic Technology

View full text Add to dashboard Cite

The performance of pulsed coherent Doppler lidar in estimating aircraft trailing wake vortices by scanning across the aircraft flight track is evaluated using Monte Carlo lidar simulations of a simple vortex pair in both a nonturbulent and turbulent environment. The performance estimates are based on maximum likelihood estimates of aircraft wake vortex parameters and provide a measure of the ability of the lidar to detect and track wake vortices under the best possible conditions. Two aircraft types are considered: the Boeing 737 and the Boeing 747. Rigorous error analyses are produced by comparing the estimated parameters from numerical simulations of raw lidar data with the known input parameters of the simulation. It is shown that the probability density functions for the estimates are approximately Gaussian and the bias is very small. The main source of the bias was determined to be the movement of the vortex during the lidar scan. The estimation error is increased by the effects of a background turbulent velocity field. The trade-off between lidar pulse energy and pulse repetition frequency for the standard condition of constant laser power is also presented. It is shown that these maximum likelihood estimates provide accurate detection and tracking of the key vortex parameters for a simple vortex model, with and without background turbulence.

show abstract

“…where c is light speed, and 0 is the laser wavelength corresponding to frequency f 0 [11][12][13] . From the digitally sampled and time-gated backscattering signals of coherent detection by lidar, the array of Doppler spectra (spectra of the power) at different ranges and scan angles are obtained.…”

Section: Fig2 Velocity Distribution Of Wake Vortices Of A340mentioning

confidence: 99%

Design of airport wake vortex monitoring system based on 1.5-μm pulsed coherent Doppler lidar

et al. 2011

Optoelectron. Lett.

View full text Add to dashboard Cite

Tianjin University of Technology and Springer-Verlag Berlin Heidelberg 2011 C To shun the vortex hazard, the airport wake vortex monitoring system based on 1.5-m pulsed coherent Doppler lidar is designed successfully in this paper. Based on the realistic analytical model, the wake vortex generated by airbus A340 under typical flight condition is simulated. Then the principle of airport wake vortex monitoring is introduced, and the work flow of the monitoring system is also presented. Moreover, based on the mechanism of vortex coherent detection and typical system parameters, both detection SNR and detection precision are obtained through numerical simulations. When the system outputs 2 J energy, the coherent detection SNR at 10 km distance is up to 23.452, and detection precision can reach 0.328 m/s. With the wake vortex monitoring experiment of A340, some vortex parameters are estimated. Due to these results comparatively coinciding with the previous simulation conclusions, the ability of Doppler lidar for full-scale wake vortex characterization and real time measurement is demonstrated. The study shows that the wake vortex detection based on 1.5-m pulsed coherent Doppler lidar has the advantages of high accuracy and far distance, and the designed airport wake vortex monitoring system has proved to be effective and feasible, which has significant development and application prospect in the aspect of assuring flight security and increasing airport capacity.

show abstract

Coherent Laser Radar and the Problem of Aircraft Wake Vortices

Cited by 30 publications

References 5 publications

Lidar for Turbine Control: March 1, 2005 - November 30, 2005

Lidar for Turbine Control: March 1, 2005 - November 30, 2005

Maximum Likelihood Estimates of Vortex Parameters from Simulated Coherent Doppler Lidar Data

Design of airport wake vortex monitoring system based on 1.5-μm pulsed coherent Doppler lidar

Contact Info

Product

Resources

About