Abstract

In lidar systems it is often advantageous or indeed necessary to reduce the field of view of the receiver. This reduction places a stringent demand on the accurate alignment of the axes of the transmitter and receiver. If this condition is not met an erroneous signal may be recorded. A simple apparatus for producing a parallel alignment of the axes is presented. A method for checking the alignment of the axes in a lidar system is also examined.

© 1987 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. K. Sassen, G. C. Dodd, “Lidar Crossover Function and Misalignment Effects,” Appl. Opt. 21, 3162 (1982).
    [CrossRef] [PubMed]
  2. K. N. Liou, R. M. Schotland, “Multiple Backscattering and Depolarisation from Water Clouds for a Pulsed Lidar System,” J. Atmos. Sci. 28, 772 (1971).
    [CrossRef]
  3. K. Bartusek, “Optical Studies of the Upper Atmosphere,” Ph.D. Thesis, Department of Physics, U. Adelaide, South Australia (1970).
  4. T. Halldorsson, J. Langerholc, “Geometrical Form Factors for the Lidar Function,” Appl. Opt. 17, 240 (1978).
    [CrossRef] [PubMed]
  5. Y. Sasano, H. Shimuzu, N. Takeuchi, M. Okuda, “Geometrical Form Factor in the Laser Radar Equation: an Experimental Determination,” Appl. Opt. 18, 3908 (1979).
    [CrossRef] [PubMed]
  6. J. Harms, “Lidar Return Signals for Coaxial and Noncoaxial Systems with Central Obstruction,” Appl. Opt. 18, 1559 (1979).
    [CrossRef] [PubMed]

1982 (1)

1979 (2)

1978 (1)

1971 (1)

K. N. Liou, R. M. Schotland, “Multiple Backscattering and Depolarisation from Water Clouds for a Pulsed Lidar System,” J. Atmos. Sci. 28, 772 (1971).
[CrossRef]

Bartusek, K.

K. Bartusek, “Optical Studies of the Upper Atmosphere,” Ph.D. Thesis, Department of Physics, U. Adelaide, South Australia (1970).

Dodd, G. C.

Halldorsson, T.

Harms, J.

Langerholc, J.

Liou, K. N.

K. N. Liou, R. M. Schotland, “Multiple Backscattering and Depolarisation from Water Clouds for a Pulsed Lidar System,” J. Atmos. Sci. 28, 772 (1971).
[CrossRef]

Okuda, M.

Sasano, Y.

Sassen, K.

Schotland, R. M.

K. N. Liou, R. M. Schotland, “Multiple Backscattering and Depolarisation from Water Clouds for a Pulsed Lidar System,” J. Atmos. Sci. 28, 772 (1971).
[CrossRef]

Shimuzu, H.

Takeuchi, N.

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 (4)

Fig. 1
Fig. 1

Lidar system and the alignment apparatus.

Fig. 2
Fig. 2

Geometry of the lidar field of view in the overlap region.

Fig. 3
Fig. 3

Method for checking the alignment of the lidar axes. The dashed curves show the results for a noncoplanar system (θ = 0.5 mrad, δ = −0.5 mrad).

Fig. 4
Fig. 4

Checking the alignment of a lidar system.

Tables (1)

Tables Icon

Table I Parameters Determined by the Alignment Testing Method

Equations (27)

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

y ( Z ) = Z · ( tan α i ) + W r i .
y ( Z ) = Z · ( tan α i ) - W r i
y ( Z ) = Z · tan ( α t - δ ) + ( S + W t ) ,
y ( Z ) = Z · tan ( - α t - δ ) + ( S - W t ) .
y ( Z ) = Z · a + b ,
y ( Z ) = Z · c + d .
α t = ( a - c ) / 2 ,
δ = - ( a + c ) / 2 ,
S = ( b + d ) / 2 ,
W t = ( b - d ) / 2.
R 1 = α t Z + W t ,
R 2 = α r Z + W r ,
R = [ ( Z θ ) 2 + ( S - Z δ ) 2 ] 1 / 2 .
R 1 + R 2 = R when Z = Z 1 and Z = Z 4 ,
R 2 - R 1 = R when Z = Z 2 and Z = Z 3 .
( α t + α r ) Z + ( W t + W r ) = [ Z 2 ( θ 2 + δ 2 ) - 2 S δ Z + S 2 ] 1 / 2 .
[ ( α t + α r ) 2 - ( θ 2 + δ 2 ) ] Z 2 + 2 [ ( W t + W r ) ( α t + α r ) + S δ ] Z + [ ( W t + W r ) 2 - S 2 ] = 0 ,
Z 1 , 4 = - [ ( W t + W r ) ( α t + α r ) + S δ ] ( α t + α r ) 2 - ( θ 2 + δ 2 ) ± { [ ( W t + W r ) ( α t + α r ) + S δ ] 2 - [ ( α t + α r ) 2 - ( θ 2 + δ 2 ) ] [ ( W t + W r ) 2 - S 2 ] } 1 / 2 ( α t + α r ) 2 - ( θ 2 + δ 2 ) .
Z 2 , 3 = - [ ( W r - W t ) ( α r - α t ) + S δ ] ( α r - α t ) 2 - ( θ 2 + δ 2 ) ± { [ ( W r - W t ) ( α r - α t ) + S δ ] 2 - [ ( α r - α t ) 2 - ( θ 2 + δ 2 ) ] [ ( W r - W t ) 2 - S 2 ] } 1 / 2 ( α r - α t ) 2 - ( θ 2 + δ 2 ) .
r f + R f < r a ,
W r f / z + ( R 1 + R ) f / z < f α r ,
R 1 + R < α r Z - W r = R 2 - 2 W r .
( α r - α t ) Z - ( W r + W t ) = [ Z 2 ( θ 2 + δ 2 ) - 2 S δ Z + S 2 ] 1 / 2 .
[ ( α r - α t ) 2 - ( θ 2 + δ 2 ) Z 2 + 2 [ S δ - ( α r - α t ) ( W r + W t ) ] Z + [ ( W r + W t ) 2 - S 2 ] = 0 ,
Z 5 , 6 = - [ S δ - ( W r + W t ) ( α r - α t ) ] ( α r - α t ) 2 - ( θ 2 + δ 2 ) ± { [ S δ - ( W r + W t ) ( α r - α t ) ] 2 - [ ( α r - α t ) 2 - ( θ 2 + θ 2 ) ] [ ( W r + W t ) 2 - S 2 ] } 1 / 2 ( α r - α t ) 2 - ( θ 2 + δ 2 ) .
Z i = S + ( - 1 ) i ( W r + W t ) δ - ( - 1 ) i ( α r + α t ) ,             ( i = 1 or 4 ) , Z j = S - ( - 1 ) j ( W r - W t ) δ + ( - 1 ) j ( α r + α t ) ,             ( j = 2 or 3 ) , Z k = S - ( - 1 ) k ( W r + W t ) δ + ( - 1 ) k ( α r - α t ) ,             ( k = 5 or 6 ) .
Z 1 = S - ( W r + W t ) ( α r + α t ) ,             Z 2 = S - ( W r - W t ) ( α r - α t ) , Z 5 = S + ( W r + W t ) ( α r - α t ) .

Metrics