Abstract

A method is proposed for using dual fields of view to allow remote sensing of the sea’s optical scattering coefficient from a laser-based airborne hydrographic system. The method depends on measurement of the rate of decay of the detected volume backscatter from a pulse of laser energy directed into the ocean and is, therefore, inherently independent of system gain calibration. The method builds on previous Monto Carlo studies of multiple scattering within the ocean bulk. An appropriate choice of fields of view allows determination of the scattering coefficient over a range appropriate to hydrographic interest in coastal waters. Limited data from flights of the WRELADS laser airborne hydrographic system support the applicability of the concept.

© 1986 Optical Society of America

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References

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  1. G. L. Clarke, “The Significance of Spectral Changes in Light Scattered by the Sea,” in Remote Sensing in Ecology, P. L. Johnson, Ed. (U. Georgia Press, Athens, 1969).
  2. F.E. Hoge, R. N. Swift, “Airborne Dual Laser Excitation and Mapping of Phytaplankton Photopigments in a Gulf Stream Warm Core Ring,” Appl. Opt. 22, 2272 (1983).
    [CrossRef] [PubMed]
  3. F. E. Hoge, R. N. Swift, “Experimental Feasibility of the Airborne Measurement of Absolute Oil Fluorescence Spectral Conversion Efficiency,” Appl. Opt. 22, 37 (1982).
    [CrossRef]
  4. W. H. Wilson, R. W. Austin, “Remote Sensing of Ocean Colour,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 23 (1978).
  5. M. Bristow, D. Nielsen, D. Bundy, R. Furtek, “Use of Water Raman Emission to Correct Airborne Laser Fluoresensor Data for Effects of Water Optical Attenuation,” Appl. Opt. 20, 2889 (1981).
    [CrossRef] [PubMed]
  6. D. M. Phillips, R. H. Abbot, M. F. Penny, “Remote Sensing of Sea Water Turbidity with an Airborne Laser System,” J. Phys. D 17, 1749 (1984).
    [CrossRef]
  7. G. D. Hickman, J. E. Hogg, “Application of an Airborne Pulsed Laser for Near Shore Bathymetric Measurements,” Remote Sensing Environ. 1, 47 (1969).
    [CrossRef]
  8. M. F. Penny et al., “Airborne Laser Hydrography in Australia,” Appl. Opt. 25, 2046 (1986).
    [CrossRef] [PubMed]
  9. B. Billard, R. H. Abbot, M. F. Penny, “Modelling Depth Bias in an Airborne Laser Hydrographic System,” Appl. Opt. 25, 2089 (1986).
    [CrossRef] [PubMed]
  10. G. C. Guenther, R. W. L. Thomas, “Effects of Propagation-Induced Pulse Stretching in Airborne Laser Hydrography,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 7, 287 (1984).
    [CrossRef]
  11. J. G. Hirschberg, A. W. Wouters, J. D. Byrne, “Laser Measure of Sea Salinity, Temperature and Turbidity in Depth,” Adv. Thermal Eng. 5, 157 (1967).
  12. B. Billard, R. H. Abbot, M. F. Penny “Airborne Estimation of Sea Turbidity Parameters from the WRELADS Laser Airborne Depth Sounder,” Appl. Opt. 25, 2080 (1986).
    [CrossRef] [PubMed]
  13. H. R. Gordon, O. B. Brown, M. M. Jacobs “Computed Relationships between the Inherent and Apparant Optical Properties of a Flat Homogeneous Ocean,” Appl. Opt. 14, 417 (1975).
    [CrossRef] [PubMed]
  14. L. R. Poole, D. D. Venable, J. W. Campbell, “Semianalytic Monte Carlo Radiative Transfer Model for Oceanographic Lidar Systems,” Appl. Opt. 20, 3653 (1981).
    [CrossRef] [PubMed]
  15. D. M. Phillips, B. W. Koerber, “A Theoretical Study of an Airborne Laser Technique for Determining Sea Water Turbidity,” Aust. J. Phys. 37, 75 (1984).
  16. R. F. Lutomirski, “An Analytic Model for Optical Beam Propagation through the Marine Boundary Layer,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 110 (1978).
  17. H. T. Yura “Propagation of Finite Cross-Section Laser Beams in Sea Water,” Appl. Opt. 12, 108 (1973).
    [CrossRef] [PubMed]
  18. L. C. Bobb, G. Ferguson, M. Rankin, P. R. Manzo, “Ocean Surface Distortion Analysis and Experiment,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 148 (1978).
  19. W. H. Wilson, “Spreading of Light Beams in Ocean Water,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 6, 64 (1979).
  20. J. G. Shannon, “Correlation of Beam and Diffuse Attenuation Coefficients Measured in Selected Ocean Waters,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 3, 3 (1975).
  21. J. T. O. Kirk, “Monte Carlo Study of the Nature of the Underwater Light Field in, and the Relationships between, Optical Properties of, Turbid Yellow Waters,” Aust. J. Mar. Freshwater Res. 32, 517 (1981).
    [CrossRef]
  22. T. J. Petzold, “Volume Scattering Functions for Selected Waters,” Scripps Institution of Oceanography, U. California (1972), SIO Ref. 72–78.
  23. H. R. Gordon, R. C. Smith, J. R. V. Zaneveld, “Introduction to Ocean Optics,” Proc. Soc. Photo. Opt. Instrum. Eng.Ocean Optics 6, 14 (1979).
  24. H. R. Gordon, “Interpretation of Airborne Oceanic Lidar: Effects of Multiple Scattering,” Appl. Opt. 21, 2996 (1982).
    [CrossRef] [PubMed]
  25. G. Kullenberg, “Scattering of Light by Sargasso Sea Water,” Deep Sea Res. 15, 423 (1968).
  26. G. C. Guenther, R. W. L. Thomas, “Prediction and Correction of Propagation-Induced Depth Measurement Biases Plus Signal Attenuation and Beam Spreading for Airborne Laser Hydrography,” NOAA Tech. Rep. 106, 121 (1984).
  27. M. F. Penny, Electronics Research Laboratory, GPO Box 2151, Adelaide, South Australia; personal communication.

1986 (3)

1984 (3)

D. M. Phillips, R. H. Abbot, M. F. Penny, “Remote Sensing of Sea Water Turbidity with an Airborne Laser System,” J. Phys. D 17, 1749 (1984).
[CrossRef]

G. C. Guenther, R. W. L. Thomas, “Effects of Propagation-Induced Pulse Stretching in Airborne Laser Hydrography,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 7, 287 (1984).
[CrossRef]

D. M. Phillips, B. W. Koerber, “A Theoretical Study of an Airborne Laser Technique for Determining Sea Water Turbidity,” Aust. J. Phys. 37, 75 (1984).

1983 (1)

1982 (2)

1981 (3)

1979 (2)

H. R. Gordon, R. C. Smith, J. R. V. Zaneveld, “Introduction to Ocean Optics,” Proc. Soc. Photo. Opt. Instrum. Eng.Ocean Optics 6, 14 (1979).

W. H. Wilson, “Spreading of Light Beams in Ocean Water,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 6, 64 (1979).

1978 (3)

W. H. Wilson, R. W. Austin, “Remote Sensing of Ocean Colour,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 23 (1978).

L. C. Bobb, G. Ferguson, M. Rankin, P. R. Manzo, “Ocean Surface Distortion Analysis and Experiment,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 148 (1978).

R. F. Lutomirski, “An Analytic Model for Optical Beam Propagation through the Marine Boundary Layer,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 110 (1978).

1975 (2)

H. R. Gordon, O. B. Brown, M. M. Jacobs “Computed Relationships between the Inherent and Apparant Optical Properties of a Flat Homogeneous Ocean,” Appl. Opt. 14, 417 (1975).
[CrossRef] [PubMed]

J. G. Shannon, “Correlation of Beam and Diffuse Attenuation Coefficients Measured in Selected Ocean Waters,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 3, 3 (1975).

1973 (1)

1969 (1)

G. D. Hickman, J. E. Hogg, “Application of an Airborne Pulsed Laser for Near Shore Bathymetric Measurements,” Remote Sensing Environ. 1, 47 (1969).
[CrossRef]

1968 (1)

G. Kullenberg, “Scattering of Light by Sargasso Sea Water,” Deep Sea Res. 15, 423 (1968).

1967 (1)

J. G. Hirschberg, A. W. Wouters, J. D. Byrne, “Laser Measure of Sea Salinity, Temperature and Turbidity in Depth,” Adv. Thermal Eng. 5, 157 (1967).

Abbot, R. H.

Austin, R. W.

W. H. Wilson, R. W. Austin, “Remote Sensing of Ocean Colour,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 23 (1978).

Billard, B.

Bobb, L. C.

L. C. Bobb, G. Ferguson, M. Rankin, P. R. Manzo, “Ocean Surface Distortion Analysis and Experiment,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 148 (1978).

Bristow, M.

Brown, O. B.

Bundy, D.

Byrne, J. D.

J. G. Hirschberg, A. W. Wouters, J. D. Byrne, “Laser Measure of Sea Salinity, Temperature and Turbidity in Depth,” Adv. Thermal Eng. 5, 157 (1967).

Campbell, J. W.

Clarke, G. L.

G. L. Clarke, “The Significance of Spectral Changes in Light Scattered by the Sea,” in Remote Sensing in Ecology, P. L. Johnson, Ed. (U. Georgia Press, Athens, 1969).

Ferguson, G.

L. C. Bobb, G. Ferguson, M. Rankin, P. R. Manzo, “Ocean Surface Distortion Analysis and Experiment,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 148 (1978).

Furtek, R.

Gordon, H. R.

Guenther, G. C.

G. C. Guenther, R. W. L. Thomas, “Effects of Propagation-Induced Pulse Stretching in Airborne Laser Hydrography,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 7, 287 (1984).
[CrossRef]

G. C. Guenther, R. W. L. Thomas, “Prediction and Correction of Propagation-Induced Depth Measurement Biases Plus Signal Attenuation and Beam Spreading for Airborne Laser Hydrography,” NOAA Tech. Rep. 106, 121 (1984).

Hickman, G. D.

G. D. Hickman, J. E. Hogg, “Application of an Airborne Pulsed Laser for Near Shore Bathymetric Measurements,” Remote Sensing Environ. 1, 47 (1969).
[CrossRef]

Hirschberg, J. G.

J. G. Hirschberg, A. W. Wouters, J. D. Byrne, “Laser Measure of Sea Salinity, Temperature and Turbidity in Depth,” Adv. Thermal Eng. 5, 157 (1967).

Hoge, F. E.

Hoge, F.E.

Hogg, J. E.

G. D. Hickman, J. E. Hogg, “Application of an Airborne Pulsed Laser for Near Shore Bathymetric Measurements,” Remote Sensing Environ. 1, 47 (1969).
[CrossRef]

Jacobs, M. M.

Kirk, J. T. O.

J. T. O. Kirk, “Monte Carlo Study of the Nature of the Underwater Light Field in, and the Relationships between, Optical Properties of, Turbid Yellow Waters,” Aust. J. Mar. Freshwater Res. 32, 517 (1981).
[CrossRef]

Koerber, B. W.

D. M. Phillips, B. W. Koerber, “A Theoretical Study of an Airborne Laser Technique for Determining Sea Water Turbidity,” Aust. J. Phys. 37, 75 (1984).

Kullenberg, G.

G. Kullenberg, “Scattering of Light by Sargasso Sea Water,” Deep Sea Res. 15, 423 (1968).

Lutomirski, R. F.

R. F. Lutomirski, “An Analytic Model for Optical Beam Propagation through the Marine Boundary Layer,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 110 (1978).

Manzo, P. R.

L. C. Bobb, G. Ferguson, M. Rankin, P. R. Manzo, “Ocean Surface Distortion Analysis and Experiment,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 148 (1978).

Nielsen, D.

Penny, M. F.

Petzold, T. J.

T. J. Petzold, “Volume Scattering Functions for Selected Waters,” Scripps Institution of Oceanography, U. California (1972), SIO Ref. 72–78.

Phillips, D. M.

D. M. Phillips, R. H. Abbot, M. F. Penny, “Remote Sensing of Sea Water Turbidity with an Airborne Laser System,” J. Phys. D 17, 1749 (1984).
[CrossRef]

D. M. Phillips, B. W. Koerber, “A Theoretical Study of an Airborne Laser Technique for Determining Sea Water Turbidity,” Aust. J. Phys. 37, 75 (1984).

Poole, L. R.

Rankin, M.

L. C. Bobb, G. Ferguson, M. Rankin, P. R. Manzo, “Ocean Surface Distortion Analysis and Experiment,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 148 (1978).

Shannon, J. G.

J. G. Shannon, “Correlation of Beam and Diffuse Attenuation Coefficients Measured in Selected Ocean Waters,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 3, 3 (1975).

Smith, R. C.

H. R. Gordon, R. C. Smith, J. R. V. Zaneveld, “Introduction to Ocean Optics,” Proc. Soc. Photo. Opt. Instrum. Eng.Ocean Optics 6, 14 (1979).

Swift, R. N.

Thomas, R. W. L.

G. C. Guenther, R. W. L. Thomas, “Effects of Propagation-Induced Pulse Stretching in Airborne Laser Hydrography,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 7, 287 (1984).
[CrossRef]

G. C. Guenther, R. W. L. Thomas, “Prediction and Correction of Propagation-Induced Depth Measurement Biases Plus Signal Attenuation and Beam Spreading for Airborne Laser Hydrography,” NOAA Tech. Rep. 106, 121 (1984).

Venable, D. D.

Wilson, W. H.

W. H. Wilson, “Spreading of Light Beams in Ocean Water,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 6, 64 (1979).

W. H. Wilson, R. W. Austin, “Remote Sensing of Ocean Colour,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 23 (1978).

Wouters, A. W.

J. G. Hirschberg, A. W. Wouters, J. D. Byrne, “Laser Measure of Sea Salinity, Temperature and Turbidity in Depth,” Adv. Thermal Eng. 5, 157 (1967).

Yura, H. T.

Zaneveld, J. R. V.

H. R. Gordon, R. C. Smith, J. R. V. Zaneveld, “Introduction to Ocean Optics,” Proc. Soc. Photo. Opt. Instrum. Eng.Ocean Optics 6, 14 (1979).

Adv. Thermal Eng. (1)

J. G. Hirschberg, A. W. Wouters, J. D. Byrne, “Laser Measure of Sea Salinity, Temperature and Turbidity in Depth,” Adv. Thermal Eng. 5, 157 (1967).

Appl. Opt. (10)

H. T. Yura “Propagation of Finite Cross-Section Laser Beams in Sea Water,” Appl. Opt. 12, 108 (1973).
[CrossRef] [PubMed]

H. R. Gordon, O. B. Brown, M. M. Jacobs “Computed Relationships between the Inherent and Apparant Optical Properties of a Flat Homogeneous Ocean,” Appl. Opt. 14, 417 (1975).
[CrossRef] [PubMed]

M. Bristow, D. Nielsen, D. Bundy, R. Furtek, “Use of Water Raman Emission to Correct Airborne Laser Fluoresensor Data for Effects of Water Optical Attenuation,” Appl. Opt. 20, 2889 (1981).
[CrossRef] [PubMed]

L. R. Poole, D. D. Venable, J. W. Campbell, “Semianalytic Monte Carlo Radiative Transfer Model for Oceanographic Lidar Systems,” Appl. Opt. 20, 3653 (1981).
[CrossRef] [PubMed]

H. R. Gordon, “Interpretation of Airborne Oceanic Lidar: Effects of Multiple Scattering,” Appl. Opt. 21, 2996 (1982).
[CrossRef] [PubMed]

F. E. Hoge, R. N. Swift, “Experimental Feasibility of the Airborne Measurement of Absolute Oil Fluorescence Spectral Conversion Efficiency,” Appl. Opt. 22, 37 (1982).
[CrossRef]

F.E. Hoge, R. N. Swift, “Airborne Dual Laser Excitation and Mapping of Phytaplankton Photopigments in a Gulf Stream Warm Core Ring,” Appl. Opt. 22, 2272 (1983).
[CrossRef] [PubMed]

M. F. Penny et al., “Airborne Laser Hydrography in Australia,” Appl. Opt. 25, 2046 (1986).
[CrossRef] [PubMed]

B. Billard, R. H. Abbot, M. F. Penny “Airborne Estimation of Sea Turbidity Parameters from the WRELADS Laser Airborne Depth Sounder,” Appl. Opt. 25, 2080 (1986).
[CrossRef] [PubMed]

B. Billard, R. H. Abbot, M. F. Penny, “Modelling Depth Bias in an Airborne Laser Hydrographic System,” Appl. Opt. 25, 2089 (1986).
[CrossRef] [PubMed]

Aust. J. Mar. Freshwater Res. (1)

J. T. O. Kirk, “Monte Carlo Study of the Nature of the Underwater Light Field in, and the Relationships between, Optical Properties of, Turbid Yellow Waters,” Aust. J. Mar. Freshwater Res. 32, 517 (1981).
[CrossRef]

Aust. J. Phys. (1)

D. M. Phillips, B. W. Koerber, “A Theoretical Study of an Airborne Laser Technique for Determining Sea Water Turbidity,” Aust. J. Phys. 37, 75 (1984).

Deep Sea Res. (1)

G. Kullenberg, “Scattering of Light by Sargasso Sea Water,” Deep Sea Res. 15, 423 (1968).

J. Phys. D (1)

D. M. Phillips, R. H. Abbot, M. F. Penny, “Remote Sensing of Sea Water Turbidity with an Airborne Laser System,” J. Phys. D 17, 1749 (1984).
[CrossRef]

Ocean Optics (7)

W. H. Wilson, R. W. Austin, “Remote Sensing of Ocean Colour,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 23 (1978).

L. C. Bobb, G. Ferguson, M. Rankin, P. R. Manzo, “Ocean Surface Distortion Analysis and Experiment,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 148 (1978).

W. H. Wilson, “Spreading of Light Beams in Ocean Water,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 6, 64 (1979).

J. G. Shannon, “Correlation of Beam and Diffuse Attenuation Coefficients Measured in Selected Ocean Waters,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 3, 3 (1975).

R. F. Lutomirski, “An Analytic Model for Optical Beam Propagation through the Marine Boundary Layer,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 5, 110 (1978).

G. C. Guenther, R. W. L. Thomas, “Effects of Propagation-Induced Pulse Stretching in Airborne Laser Hydrography,” Proc. Soc. Photo-Opt. Instrum. Eng.Ocean Optics 7, 287 (1984).
[CrossRef]

H. R. Gordon, R. C. Smith, J. R. V. Zaneveld, “Introduction to Ocean Optics,” Proc. Soc. Photo. Opt. Instrum. Eng.Ocean Optics 6, 14 (1979).

Remote Sensing Environ. (1)

G. D. Hickman, J. E. Hogg, “Application of an Airborne Pulsed Laser for Near Shore Bathymetric Measurements,” Remote Sensing Environ. 1, 47 (1969).
[CrossRef]

Other (4)

G. L. Clarke, “The Significance of Spectral Changes in Light Scattered by the Sea,” in Remote Sensing in Ecology, P. L. Johnson, Ed. (U. Georgia Press, Athens, 1969).

T. J. Petzold, “Volume Scattering Functions for Selected Waters,” Scripps Institution of Oceanography, U. California (1972), SIO Ref. 72–78.

G. C. Guenther, R. W. L. Thomas, “Prediction and Correction of Propagation-Induced Depth Measurement Biases Plus Signal Attenuation and Beam Spreading for Airborne Laser Hydrography,” NOAA Tech. Rep. 106, 121 (1984).

M. F. Penny, Electronics Research Laboratory, GPO Box 2151, Adelaide, South Australia; personal communication.

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Figures (12)

Fig. 1
Fig. 1

(ka)/b as a function of cR for phase functions KA and KC and a range of values of the scattering albedo ω0 (after Gordon).

Fig. 2
Fig. 2

Variation of laser beam intensity with sea depth for (a) total scattered and unscattered beam, (b) scattered beam only, and (c) unscattered beam only, using representative decay constants for coastal waters

Fig. 3
Fig. 3

Scenario for the routine measurement of forward scatter in association with an airborne laser hydrographic system

Fig. 4
Fig. 4

Measured k (m−1) as a function of receiver field of view (mR) in a single test over 20 s of flight over the Gulf of St. Vincent.

Fig. 5
Fig. 5

Sample waveform of received green energy during the tests of Fig. 4. A 4-mR block is located in the center of the receiver field of view.

Fig. 6
Fig. 6

Sample waveforms from a region of the Gulf of St. Vincent at 21-m depth. In each case the receiver field of view was 38 mR. Optical block sizes were (a) zero, (b) 4 mR, (c) 6 mR, and (d) 10 mR.

Fig. 7
Fig. 7

Backscatter envelopes from Figs. 6(b) and (c) superimposed and enlarged to highlight the differences arising from different block sizes.

Fig. 8
Fig. 8

Sample waveforms from a region of the Gulf of St. Vincent at 28-m depth. In each case the receiver field of view was 38 mR. Optical block sizes were (a) 4 mR, (b) 6 mR, and (c) 10 mR.

Fig. 9
Fig. 9

Contours of constant b in the (kS, kL) plane when VL = 40 mR and VS = 6 mR: (a) for the KA scattering phase function; (b) for the KC scattering phase function. The values of b are as marked.

Fig. 10
Fig. 10

Comparison of constant b contours for the KA (solid lines) and KC (broken lines) phase functions for three combinations of VL and Vs: (a) VL = 40 mR, VS = 6 mR; (b) VL = 40 mR, VS = 10 mR; (c) VL = 25 mR, VS = 6 mR.

Fig. 11
Fig. 11

Comparison of constant a contours for the KA (solid lines) and KC (broken lines) phase functions VL = 25 mR and VS = 6 mR. The values of a for the KA phase function are on the left.

Fig. 12
Fig. 12

Implied (kS, kL) values for data from the four indicated WRELADS flights over the Gulf of St. Vincent. The airborne data gave kL at 40 mR, while a surface vessel used a transmissometer to measure c. From this can be deduced (b, a) and hence (kS, kL) applying when VL = 25 mR and VS = 6 mR, and KA is the phase function. The individual data are superimposed on the b contours for the same VL and VS.

Equations (2)

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k S = a + b f ( a , b , R S ) , k L = a + b f ( a , b , R L ) ,
c = a + b , k L = a + b f ( a , b , R L )

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