Abstract

A coherent imaging CO2 laser radar has been built and field tested. It collects reflectance and range images from amplitude and phase measurements. Statistical analysis indicates Rayleigh distribution in the reflectance data from a military truck, the dirt ground, and an asphalt road. The reflectivities of these objects are determined to be <2.5%, obtained by comparison with laboratory reflectometer measurements.

© 1984 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. M. C. Teich, “Homodyne Detection of Infrared Detection from a Moving Diffuse Target,” Proc. IEEE 57, 786 (1969).
    [CrossRef]
  2. See, for example, “Heterodyne Systems and Technology,” NASA Conference Publication 2138 (Mar.1980).
  3. R. C. Harney, R. J. Hull, “Compact Infrared Radar Technology,” Proc. Soc. Photo-Opt. Instrum. Eng. 227, 162 (1980).
  4. J. W. Goodman, “Statistical Properties of Laser Speckle Patterns,” in Laser Speckle and Related Phenomena, J. C. Dainty, Ed. (Springer, New York, 1975).
    [CrossRef]
  5. J. Y. Wang, “Heterodyne Laser Radar SNR from a Diffuse Target Containing Multiple Glints,” Appl. Opt. 21, 464 (1982).
    [CrossRef] [PubMed]
  6. J. Y. Wang, P. A. Pruitt, “Laboratory Target Reflectance Measurements for Coherent Laser Radar Applications,” Appl. Opt. 23, 2559 (1984).
    [CrossRef] [PubMed]
  7. In our laboratory reflectometer measurements presented in Ref. 6, a narrowband filter was placed in front of the detector to block unwanted radiation. An air-cooled CO2 waveguide laser (manufactured by California Laser, Inc.) was used in the earlier experiments. It was later discovered that this laser generated double lines simultaneously, one of them being blocked by the filter. Consequently, the reported reflectivity [Proc. Soc. Photo-Opt. Instrum. Eng. 415, 28 (1983)] was off by ~25%. This problem was remedied by employing a more stable water-cooled device (from the same manufacturer), which obtained the current results.

1984 (1)

1983 (1)

In our laboratory reflectometer measurements presented in Ref. 6, a narrowband filter was placed in front of the detector to block unwanted radiation. An air-cooled CO2 waveguide laser (manufactured by California Laser, Inc.) was used in the earlier experiments. It was later discovered that this laser generated double lines simultaneously, one of them being blocked by the filter. Consequently, the reported reflectivity [Proc. Soc. Photo-Opt. Instrum. Eng. 415, 28 (1983)] was off by ~25%. This problem was remedied by employing a more stable water-cooled device (from the same manufacturer), which obtained the current results.

1982 (1)

1980 (2)

See, for example, “Heterodyne Systems and Technology,” NASA Conference Publication 2138 (Mar.1980).

R. C. Harney, R. J. Hull, “Compact Infrared Radar Technology,” Proc. Soc. Photo-Opt. Instrum. Eng. 227, 162 (1980).

1969 (1)

M. C. Teich, “Homodyne Detection of Infrared Detection from a Moving Diffuse Target,” Proc. IEEE 57, 786 (1969).
[CrossRef]

Goodman, J. W.

J. W. Goodman, “Statistical Properties of Laser Speckle Patterns,” in Laser Speckle and Related Phenomena, J. C. Dainty, Ed. (Springer, New York, 1975).
[CrossRef]

Harney, R. C.

R. C. Harney, R. J. Hull, “Compact Infrared Radar Technology,” Proc. Soc. Photo-Opt. Instrum. Eng. 227, 162 (1980).

Hull, R. J.

R. C. Harney, R. J. Hull, “Compact Infrared Radar Technology,” Proc. Soc. Photo-Opt. Instrum. Eng. 227, 162 (1980).

Pruitt, P. A.

Teich, M. C.

M. C. Teich, “Homodyne Detection of Infrared Detection from a Moving Diffuse Target,” Proc. IEEE 57, 786 (1969).
[CrossRef]

Wang, J. Y.

Appl. Opt. (2)

NASA Conference Publication 2138 (1)

See, for example, “Heterodyne Systems and Technology,” NASA Conference Publication 2138 (Mar.1980).

Proc. IEEE (1)

M. C. Teich, “Homodyne Detection of Infrared Detection from a Moving Diffuse Target,” Proc. IEEE 57, 786 (1969).
[CrossRef]

Proc. Soc. Photo-Opt. Instrum. Eng. (2)

R. C. Harney, R. J. Hull, “Compact Infrared Radar Technology,” Proc. Soc. Photo-Opt. Instrum. Eng. 227, 162 (1980).

In our laboratory reflectometer measurements presented in Ref. 6, a narrowband filter was placed in front of the detector to block unwanted radiation. An air-cooled CO2 waveguide laser (manufactured by California Laser, Inc.) was used in the earlier experiments. It was later discovered that this laser generated double lines simultaneously, one of them being blocked by the filter. Consequently, the reported reflectivity [Proc. Soc. Photo-Opt. Instrum. Eng. 415, 28 (1983)] was off by ~25%. This problem was remedied by employing a more stable water-cooled device (from the same manufacturer), which obtained the current results.

Other (1)

J. W. Goodman, “Statistical Properties of Laser Speckle Patterns,” in Laser Speckle and Related Phenomena, J. C. Dainty, Ed. (Springer, New York, 1975).
[CrossRef]

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 (18)

Fig. 1
Fig. 1

Optical schematic of heterodyne CO2 laser radar.

Fig. 2
Fig. 2

CO2 laser radar.

Fig. 3
Fig. 3

Signal processing electronics used with the CO2 laser radar.

Fig. 4
Fig. 4

View from the radar tower looking northeast.

Fig. 5
Fig. 5

View from the radar tower looking east.

Fig. 6
Fig. 6

Typical target scene.

Fig. 7
Fig. 7

Reflectance and range images at 20° depression angle (looking NE).

Fig. 8
Fig. 8

Reflectance and range images at 5° depression angle (looking NE).

Fig. 9
Fig. 9

Reflectance and range images at 5° depression angle (looking E).

Fig. 10
Fig. 10

Background-noise-suppressed range image.

Fig. 11
Fig. 11

Reflectance and background-noise-suppressed range images.

Fig. 12
Fig. 12

Reflectance histogram from flame-sprayed aluminum.

Fig. 13
Fig. 13

Range histogram from range panel region.

Fig. 14
Fig. 14

Reflectance histogram from the dirt ground.

Fig. 15
Fig. 15

Reflectance histogram from a military truck.

Fig. 16
Fig. 16

Reflectance histogram from remote background.

Fig. 17
Fig. 17

Relationship of standard deviation and signal mean from selected targets and background.

Fig. 18
Fig. 18

Relation between the signal power and the dirt background slant range.

Tables (1)

Tables Icon

Table I Reflectivities Derived from Field-Tested CO2 Lasar Radar

Equations (2)

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

P ( V ) = V σ 2 exp ( - V 2 2 σ 2 ) ,
V = 0 V P ( V ) d V = σ ( π / 2 ) , V 2 = 0 V 2 P ( V ) d V = 2 σ 2 .

Metrics