Abstract

The results of field and laboratory experiments of a novel laser radar (ladar) are presented. This ladar was designed to detect objects off the line of sight by deploying a fiber-optic relay between the launch and probe sites by monitoring the retroreflected signals. The apparatus incorporates a pulsed diode laser emitting at 1.55 μm, a wavelength that is ideal for eye safety and bears minimum loss in silica fibers. With its immediate application in transportation safety, the system issues a warning within a millisecond of detecting an obstacle in the path of a vehicle. The results of the field experiments yield signal-to-noise ratios high enough to trigger reliably an alarm with a probability of greater than 0.999 for detecting an obstacle and less than 10-12 probability of false alarms.

© 1998 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. R. DeMeis, “GPS positions itself for a starring role,” Aerospace America (May1993); P. J. Howe, “Efforts are intensified for safety on rails,” The Boston Globe (1April1996); S. R. Ditmeyer, Burlington Northern Railroad, Overland Park, Kans. (personal communication).
  2. J. W. Goodman, “Comparative performance of optical-radar detection techniques,” IEEE Trans. Aerosp. Electron. Syst. AES-2, 526–535 (1966).
    [CrossRef]
  3. H. N. Burns, C. G. Christodoulou, G. D. Boreman, “System design of a pulsed laser rangefinder,” Opt. Eng. 30, 323–329 (1991).
    [CrossRef]
  4. F. K. Knight, D. I. Klick, D. P. Ryan-Howard, J. R. Theriault, “Visible laser radar: range tomography and angle–angle range detection,” Opt. Eng. 30, 55–65 (1991).
    [CrossRef]
  5. T. J. Kane, W. J. Kozlovsky, “Coherent laser radar at 1.06 μm using Nd:YAG lasers,” Opt. Lett. 12, 239–241 (1987).
    [CrossRef] [PubMed]
  6. For example, D. G. Youmans, “Laser radar speckle and glint statistics: illustrations using AMOR data,” in Laser Radar V, R. J. Becherer, ed., Proc. SPIE1222, 43–57 (1990).
    [CrossRef]
  7. American National Standard Institute for the Safe Use of Lasers, ANSI Z136.1-1986 (American National Standard Institute, New York, 1986).
  8. M. Rioux, J. A. Beraldine, M. O’Sullivan, L. Cournoyer, “Eyesafe laser scanner for range imaging,” Appl. Opt. 30, 2219–2223 (1991).
    [CrossRef] [PubMed]
  9. R. Targ, B. C. Steakley, J. G. Hawly, L. L. Ames, P. Forney, D. Swanson, R. Stone, R. G. Otto, V. Zarifis, P. Brockman, R. S. Calloway, S. H. Klein, P. A. Robinson, “Coherent lidar airborne wind sensor II: flight test results at 2 and 10 μm,” Appl. Opt. 35, 7117–7127 (1996).
    [CrossRef] [PubMed]
  10. M. M. Tilleman, D. B. Oakes, K. Krishnaswami, “Fiberoptic relayed laser radar,” in Radar/Ladar Processing and Applications, W. J. Miceli, ed., Proc. SPIE2562, 236–243 (1995).
    [CrossRef]
  11. M. Bass, ed., Handbook of Optics (McGraw-Hill, New York, 1995).
  12. Electro-Optics Handbook, Technical Series EOH-II (RCA, Lancaster, Pa., 1974).
  13. A. V. Jelalian, Laser Radar Systems (Artech House, Norwood, Mass., 1992).
  14. M. M. Tilleman, K. Krishnaswami, “Design of a fiberoptic relayed laser radar,” Opt. Eng. 35, 3279–3284 (1996).
    [CrossRef]

1996 (2)

1991 (3)

M. Rioux, J. A. Beraldine, M. O’Sullivan, L. Cournoyer, “Eyesafe laser scanner for range imaging,” Appl. Opt. 30, 2219–2223 (1991).
[CrossRef] [PubMed]

H. N. Burns, C. G. Christodoulou, G. D. Boreman, “System design of a pulsed laser rangefinder,” Opt. Eng. 30, 323–329 (1991).
[CrossRef]

F. K. Knight, D. I. Klick, D. P. Ryan-Howard, J. R. Theriault, “Visible laser radar: range tomography and angle–angle range detection,” Opt. Eng. 30, 55–65 (1991).
[CrossRef]

1987 (1)

1966 (1)

J. W. Goodman, “Comparative performance of optical-radar detection techniques,” IEEE Trans. Aerosp. Electron. Syst. AES-2, 526–535 (1966).
[CrossRef]

Ames, L. L.

Beraldine, J. A.

Boreman, G. D.

H. N. Burns, C. G. Christodoulou, G. D. Boreman, “System design of a pulsed laser rangefinder,” Opt. Eng. 30, 323–329 (1991).
[CrossRef]

Brockman, P.

Burns, H. N.

H. N. Burns, C. G. Christodoulou, G. D. Boreman, “System design of a pulsed laser rangefinder,” Opt. Eng. 30, 323–329 (1991).
[CrossRef]

Calloway, R. S.

Christodoulou, C. G.

H. N. Burns, C. G. Christodoulou, G. D. Boreman, “System design of a pulsed laser rangefinder,” Opt. Eng. 30, 323–329 (1991).
[CrossRef]

Cournoyer, L.

DeMeis, R.

R. DeMeis, “GPS positions itself for a starring role,” Aerospace America (May1993); P. J. Howe, “Efforts are intensified for safety on rails,” The Boston Globe (1April1996); S. R. Ditmeyer, Burlington Northern Railroad, Overland Park, Kans. (personal communication).

Forney, P.

Goodman, J. W.

J. W. Goodman, “Comparative performance of optical-radar detection techniques,” IEEE Trans. Aerosp. Electron. Syst. AES-2, 526–535 (1966).
[CrossRef]

Hawly, J. G.

Jelalian, A. V.

A. V. Jelalian, Laser Radar Systems (Artech House, Norwood, Mass., 1992).

Kane, T. J.

Klein, S. H.

Klick, D. I.

F. K. Knight, D. I. Klick, D. P. Ryan-Howard, J. R. Theriault, “Visible laser radar: range tomography and angle–angle range detection,” Opt. Eng. 30, 55–65 (1991).
[CrossRef]

Knight, F. K.

F. K. Knight, D. I. Klick, D. P. Ryan-Howard, J. R. Theriault, “Visible laser radar: range tomography and angle–angle range detection,” Opt. Eng. 30, 55–65 (1991).
[CrossRef]

Kozlovsky, W. J.

Krishnaswami, K.

M. M. Tilleman, K. Krishnaswami, “Design of a fiberoptic relayed laser radar,” Opt. Eng. 35, 3279–3284 (1996).
[CrossRef]

M. M. Tilleman, D. B. Oakes, K. Krishnaswami, “Fiberoptic relayed laser radar,” in Radar/Ladar Processing and Applications, W. J. Miceli, ed., Proc. SPIE2562, 236–243 (1995).
[CrossRef]

O’Sullivan, M.

Oakes, D. B.

M. M. Tilleman, D. B. Oakes, K. Krishnaswami, “Fiberoptic relayed laser radar,” in Radar/Ladar Processing and Applications, W. J. Miceli, ed., Proc. SPIE2562, 236–243 (1995).
[CrossRef]

Otto, R. G.

Rioux, M.

Robinson, P. A.

Ryan-Howard, D. P.

F. K. Knight, D. I. Klick, D. P. Ryan-Howard, J. R. Theriault, “Visible laser radar: range tomography and angle–angle range detection,” Opt. Eng. 30, 55–65 (1991).
[CrossRef]

Steakley, B. C.

Stone, R.

Swanson, D.

Targ, R.

Theriault, J. R.

F. K. Knight, D. I. Klick, D. P. Ryan-Howard, J. R. Theriault, “Visible laser radar: range tomography and angle–angle range detection,” Opt. Eng. 30, 55–65 (1991).
[CrossRef]

Tilleman, M. M.

M. M. Tilleman, K. Krishnaswami, “Design of a fiberoptic relayed laser radar,” Opt. Eng. 35, 3279–3284 (1996).
[CrossRef]

M. M. Tilleman, D. B. Oakes, K. Krishnaswami, “Fiberoptic relayed laser radar,” in Radar/Ladar Processing and Applications, W. J. Miceli, ed., Proc. SPIE2562, 236–243 (1995).
[CrossRef]

Youmans, D. G.

For example, D. G. Youmans, “Laser radar speckle and glint statistics: illustrations using AMOR data,” in Laser Radar V, R. J. Becherer, ed., Proc. SPIE1222, 43–57 (1990).
[CrossRef]

Zarifis, V.

Appl. Opt. (2)

IEEE Trans. Aerosp. Electron. Syst. (1)

J. W. Goodman, “Comparative performance of optical-radar detection techniques,” IEEE Trans. Aerosp. Electron. Syst. AES-2, 526–535 (1966).
[CrossRef]

Opt. Eng. (3)

H. N. Burns, C. G. Christodoulou, G. D. Boreman, “System design of a pulsed laser rangefinder,” Opt. Eng. 30, 323–329 (1991).
[CrossRef]

F. K. Knight, D. I. Klick, D. P. Ryan-Howard, J. R. Theriault, “Visible laser radar: range tomography and angle–angle range detection,” Opt. Eng. 30, 55–65 (1991).
[CrossRef]

M. M. Tilleman, K. Krishnaswami, “Design of a fiberoptic relayed laser radar,” Opt. Eng. 35, 3279–3284 (1996).
[CrossRef]

Opt. Lett. (1)

Other (7)

R. DeMeis, “GPS positions itself for a starring role,” Aerospace America (May1993); P. J. Howe, “Efforts are intensified for safety on rails,” The Boston Globe (1April1996); S. R. Ditmeyer, Burlington Northern Railroad, Overland Park, Kans. (personal communication).

For example, D. G. Youmans, “Laser radar speckle and glint statistics: illustrations using AMOR data,” in Laser Radar V, R. J. Becherer, ed., Proc. SPIE1222, 43–57 (1990).
[CrossRef]

American National Standard Institute for the Safe Use of Lasers, ANSI Z136.1-1986 (American National Standard Institute, New York, 1986).

M. M. Tilleman, D. B. Oakes, K. Krishnaswami, “Fiberoptic relayed laser radar,” in Radar/Ladar Processing and Applications, W. J. Miceli, ed., Proc. SPIE2562, 236–243 (1995).
[CrossRef]

M. Bass, ed., Handbook of Optics (McGraw-Hill, New York, 1995).

Electro-Optics Handbook, Technical Series EOH-II (RCA, Lancaster, Pa., 1974).

A. V. Jelalian, Laser Radar Systems (Artech House, Norwood, Mass., 1992).

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 (10)

Fig. 1
Fig. 1

Illustration of the ladar probing a region 5 km ahead of the train, with the transceiver mounted on the train.

Fig. 2
Fig. 2

Schematic of the fiber-optic-relayed laser radar.

Fig. 3
Fig. 3

Top view of a probed region with an obstacle present and a comparison of the retroreflected signal with and without an obstacle.

Fig. 4
Fig. 4

Schematics of the optomechanical subsystems: (a) transceiver, (b) entrance coupler, (c) exit coupler.

Fig. 5
Fig. 5

Oscilloscope traces with no obstacles in the path: (a) launched laser pulse where X = 50 ns/div and Y = 50 mV/div; (b) received sequence of six pulses where X = 0.2 μs/div, Y upper = 0.2 V/div, and Y lower = 0.1 V/div.

Fig. 6
Fig. 6

Examples of the received sequence of six pulses with obstacles in the path where X = 0.2 μs/div, Y upper = 0.2 V/div, and Y lower = 0.1 V/div.

Fig. 7
Fig. 7

Measured SNR’s as a function of the optical density of the path. The parameter is the laser power at launch.

Fig. 8
Fig. 8

Oscilloscope traces of the received signal with no obstacles in the path where X = 200 ns/div and Y = 20 mV/div.

Fig. 9
Fig. 9

Examples of the received signal with obstacles in the path where X = 200 ns/div and Y = 20 mV/div.

Fig. 10
Fig. 10

Calculations for the probability of detection (P D ) versus the probability of false alarm (P FA) for various signal redundancies (N): (a) SNR of 4 and (b) SNR of 7.

Tables (2)

Tables Icon

Table 1 Loss and Gain of Signal in the Ladar System

Tables Icon

Table 2 Transmittance at 1550 nm for Various Distances in the Lower Atmosphere

Equations (2)

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

P S = η 1 η 2 W S Δ λ   A D R 2 exp - α R ,
P D P SNR - P - 1 1 - P FA 1 / N N ,

Metrics