Abstract

We discuss an optical fiber-based continuous-wave coherent laser system for measuring the wind speed in undisturbed air ahead of an aircraft. The operational principles of the instrument are described, and estimates of performance are presented. The instrument is demonstrated as a single line of sight, and data from the inaugural test flight of August 2010 is presented. The system was successfully operated under various atmospheric conditions, including cloud and clear air up to 12km (40,300ft).

© 2011 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. R. M. Muñioz, H. W. Mocker, and L. Koehler, “Airborne laser Doppler velocimeter,” Appl. Opt. 13, 2890–2898 (1974).
    [CrossRef] [PubMed]
  2. R. Keeler, R. Serafin, R. Schwiesow, D. Lenschow, J. M. Vaughan, and A. Woodfield, “An airborne laser air motion sensing system. part I: concept and preliminary experiment,” J. Atmos. Ocean. Technol. 4, 113–127 (1987).
    [CrossRef]
  3. L. Kristensen and D. Lenschow, “An airborne laser air motion sensing system. part II: design criteria and measurement possibilities,” J. Atmos. Ocean. Technol. 4, 128–138 (1987).
    [CrossRef]
  4. C. M. Sonnenschein and F. A. Horrigan, “Signal-to-noise relationships for coaxial systems that heterodyne backscatter from the atmosphere,” Appl. Opt. 10, 1600–1604 (1971).
    [CrossRef] [PubMed]
  5. C. J. Karlsson, F. A. Olsson, D. Letalick, and M. Harris, “All-fiber multifunction continuous-wave coherent laser radar at 1.55 μm for range, speed, vibration, and wind measurements,” Appl. Opt. 39, 3716–3726 (2000).
    [CrossRef]
  6. J. M. Vaughan, D. W. Brown, C. Nash, S. B. Alejandaro, and G. G. Koenig, “Atlantic atmospheric aerosol studies 2. compendium of airborne backscatter measurements at 10.6 μm,” J. Geophys. Res. 100, 1043–1065 (1995).
    [CrossRef]
  7. V. Srivastava, J. Rothermel, A. D. Clarke, J. D. Spinhirne, R. T. Menzies, D. R. Cutten, M. A. Jarzembski, D. A. Bowdle, and E. W. McCaul, “Wavelength dependence of backscatter by use of aerosol microphysics and lidar data sets: application to 2.1 μm wavelength for space-based and airborne lidars,” Appl. Opt. 40, 4759–4769 (2001).
    [CrossRef]
  8. P. Werle, “Accuracy and precision of laser spectrometers for trace gas sensing in the presence of optical fringes and atmospheric turbulence,” Appl. Phys. B (to be published).
    [CrossRef]
  9. R. B. Stull, An Introduction to Boundary Layer Meteorology (Kluwer Academic, 1988).

2001

2000

1995

J. M. Vaughan, D. W. Brown, C. Nash, S. B. Alejandaro, and G. G. Koenig, “Atlantic atmospheric aerosol studies 2. compendium of airborne backscatter measurements at 10.6 μm,” J. Geophys. Res. 100, 1043–1065 (1995).
[CrossRef]

1987

R. Keeler, R. Serafin, R. Schwiesow, D. Lenschow, J. M. Vaughan, and A. Woodfield, “An airborne laser air motion sensing system. part I: concept and preliminary experiment,” J. Atmos. Ocean. Technol. 4, 113–127 (1987).
[CrossRef]

L. Kristensen and D. Lenschow, “An airborne laser air motion sensing system. part II: design criteria and measurement possibilities,” J. Atmos. Ocean. Technol. 4, 128–138 (1987).
[CrossRef]

1974

1971

Alejandaro, S. B.

J. M. Vaughan, D. W. Brown, C. Nash, S. B. Alejandaro, and G. G. Koenig, “Atlantic atmospheric aerosol studies 2. compendium of airborne backscatter measurements at 10.6 μm,” J. Geophys. Res. 100, 1043–1065 (1995).
[CrossRef]

Bowdle, D. A.

Brown, D. W.

J. M. Vaughan, D. W. Brown, C. Nash, S. B. Alejandaro, and G. G. Koenig, “Atlantic atmospheric aerosol studies 2. compendium of airborne backscatter measurements at 10.6 μm,” J. Geophys. Res. 100, 1043–1065 (1995).
[CrossRef]

Clarke, A. D.

Cutten, D. R.

Harris, M.

Horrigan, F. A.

Jarzembski, M. A.

Karlsson, C. J.

Keeler, R.

R. Keeler, R. Serafin, R. Schwiesow, D. Lenschow, J. M. Vaughan, and A. Woodfield, “An airborne laser air motion sensing system. part I: concept and preliminary experiment,” J. Atmos. Ocean. Technol. 4, 113–127 (1987).
[CrossRef]

Koehler, L.

Koenig, G. G.

J. M. Vaughan, D. W. Brown, C. Nash, S. B. Alejandaro, and G. G. Koenig, “Atlantic atmospheric aerosol studies 2. compendium of airborne backscatter measurements at 10.6 μm,” J. Geophys. Res. 100, 1043–1065 (1995).
[CrossRef]

Kristensen, L.

L. Kristensen and D. Lenschow, “An airborne laser air motion sensing system. part II: design criteria and measurement possibilities,” J. Atmos. Ocean. Technol. 4, 128–138 (1987).
[CrossRef]

Lenschow, D.

L. Kristensen and D. Lenschow, “An airborne laser air motion sensing system. part II: design criteria and measurement possibilities,” J. Atmos. Ocean. Technol. 4, 128–138 (1987).
[CrossRef]

R. Keeler, R. Serafin, R. Schwiesow, D. Lenschow, J. M. Vaughan, and A. Woodfield, “An airborne laser air motion sensing system. part I: concept and preliminary experiment,” J. Atmos. Ocean. Technol. 4, 113–127 (1987).
[CrossRef]

Letalick, D.

McCaul, E. W.

Menzies, R. T.

Mocker, H. W.

Muñioz, R. M.

Nash, C.

J. M. Vaughan, D. W. Brown, C. Nash, S. B. Alejandaro, and G. G. Koenig, “Atlantic atmospheric aerosol studies 2. compendium of airborne backscatter measurements at 10.6 μm,” J. Geophys. Res. 100, 1043–1065 (1995).
[CrossRef]

Olsson, F. A.

Rothermel, J.

Schwiesow, R.

R. Keeler, R. Serafin, R. Schwiesow, D. Lenschow, J. M. Vaughan, and A. Woodfield, “An airborne laser air motion sensing system. part I: concept and preliminary experiment,” J. Atmos. Ocean. Technol. 4, 113–127 (1987).
[CrossRef]

Serafin, R.

R. Keeler, R. Serafin, R. Schwiesow, D. Lenschow, J. M. Vaughan, and A. Woodfield, “An airborne laser air motion sensing system. part I: concept and preliminary experiment,” J. Atmos. Ocean. Technol. 4, 113–127 (1987).
[CrossRef]

Sonnenschein, C. M.

Spinhirne, J. D.

Srivastava, V.

Stull, R. B.

R. B. Stull, An Introduction to Boundary Layer Meteorology (Kluwer Academic, 1988).

Vaughan, J. M.

J. M. Vaughan, D. W. Brown, C. Nash, S. B. Alejandaro, and G. G. Koenig, “Atlantic atmospheric aerosol studies 2. compendium of airborne backscatter measurements at 10.6 μm,” J. Geophys. Res. 100, 1043–1065 (1995).
[CrossRef]

R. Keeler, R. Serafin, R. Schwiesow, D. Lenschow, J. M. Vaughan, and A. Woodfield, “An airborne laser air motion sensing system. part I: concept and preliminary experiment,” J. Atmos. Ocean. Technol. 4, 113–127 (1987).
[CrossRef]

Werle, P.

P. Werle, “Accuracy and precision of laser spectrometers for trace gas sensing in the presence of optical fringes and atmospheric turbulence,” Appl. Phys. B (to be published).
[CrossRef]

Woodfield, A.

R. Keeler, R. Serafin, R. Schwiesow, D. Lenschow, J. M. Vaughan, and A. Woodfield, “An airborne laser air motion sensing system. part I: concept and preliminary experiment,” J. Atmos. Ocean. Technol. 4, 113–127 (1987).
[CrossRef]

Appl. Opt.

J. Atmos. Ocean. Technol.

R. Keeler, R. Serafin, R. Schwiesow, D. Lenschow, J. M. Vaughan, and A. Woodfield, “An airborne laser air motion sensing system. part I: concept and preliminary experiment,” J. Atmos. Ocean. Technol. 4, 113–127 (1987).
[CrossRef]

L. Kristensen and D. Lenschow, “An airborne laser air motion sensing system. part II: design criteria and measurement possibilities,” J. Atmos. Ocean. Technol. 4, 128–138 (1987).
[CrossRef]

J. Geophys. Res.

J. M. Vaughan, D. W. Brown, C. Nash, S. B. Alejandaro, and G. G. Koenig, “Atlantic atmospheric aerosol studies 2. compendium of airborne backscatter measurements at 10.6 μm,” J. Geophys. Res. 100, 1043–1065 (1995).
[CrossRef]

Other

P. Werle, “Accuracy and precision of laser spectrometers for trace gas sensing in the presence of optical fringes and atmospheric turbulence,” Appl. Phys. B (to be published).
[CrossRef]

R. B. Stull, An Introduction to Boundary Layer Meteorology (Kluwer Academic, 1988).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (8)

Fig. 1
Fig. 1

Predicted instrument signal to noise as a function of aircraft altitude. Inputs included 3 W transmitted optical power and 200,000 spectra averaged—equivalent to 1 Hz data rate.

Fig. 2
Fig. 2

Optical setup of the LAMS. Component location on the aircraft is indicated by the large shaded boxes. Note that the end of the fiber was polished at a shallow angle so that a small percentage of the transmitted beam was reflected upon exit. The reflection forms the LO, and for this work, the fiber was angle polished to have a 37 dB reflection.

Fig. 3
Fig. 3

Detail of the prototype LAMS wing pod used for demonstration and validation.

Fig. 4
Fig. 4

LAMS installation for the NCAR GV. The laser and detector are cabin mounted, with fibers running in the wing connecting them to a small optical bench that was used to focus the laser at a fixed location about 16 m in front of the nose of the aircraft.

Fig. 5
Fig. 5

This figure shows the 1 Hz data for the test flight on 3 August 2010. The top panel shows true airspeed derived from avionics Pitot-static tubes, TASA, fuselage static Pitot tube and static pressure port, TASF, and the LAMS. The aircraft altitude (in kilometers) is shown on the right y axis. The middle panel is a plot of the difference between LAMS and the two in situ derived true airspeeds. The bottom panel is a plot of the LAMS SNR on the left axis and the square root of the aerosol concentration, SQRT(CONC), on the right y axis.

Fig. 6
Fig. 6

Allan variance plot of the TAS difference data from time series from 21:57 to 22:03 UTC. The slope of the dashed line is fixed at τ 0.5 .

Fig. 7
Fig. 7

Sample high-rate time series of the true airspeed from the LAMS and the fuselage pressure differential sensor at low altitude. The 6 min segment was at a level altitude of 2660 m .

Fig. 8
Fig. 8

Velocity power spectrum of the time series of the LAMS and the fuselage differential pressure system from the time period 20:20 to 20.26 UTC. The slope of the dashed line indicates Kolmogorov’s 5 / 3 frequency dependence in the inertial subrange.

Equations (6)

Equations on this page are rendered with MathJax. Learn more.

n T = P T h ν ,
v = λ f D 2 ,
i s 2 = n T n ref β π η 2 G 2 e 2 π r t 2 0 ( L 2 [ 1 + ( π r t λ L ) 2 ( 1 L f ) 2 ] ) 1 d L ,
i s 2 = n T n ref β π η 2 G 2 e 2 λ [ π 2 + a tan ( π r t 2 λ f ) ] .
i n 2 = 2 η G 2 e 2 n ref B ,
SNR = [ η P T β π λ 2 B h ν ( π 2 + a tan ( π r t 2 λ f ) ) ] 1 / 2 ,

Metrics