The Optical Scatter Channel and Its Properties

  • Sherman Karp
  • Robert M. Gagliardi
  • Steven E. Moran
  • Larry B. Stotts
Part of the Applications of Communications Theory book series (ACTH)

Abstract

With the introduction of ultraviolet, visible, and infrared technologies in the areas of communications and surveillance, it has become necessary to account for the atmospheric and oceanic influences on such systems—in specific terms, the effects of particulate multiple scattering on optical radiation transfer. This is because the haze, fog, rain, and clouds comprising most of the atmospheric channel, and the yellow substance and small “sea animals” in the marine channel, cause the majority of the degradation suffered by the information-containing signal traversing that channel. Recall from the previous chapter that atmospheric and marine turbulence can generate significant wavefront distortions of a signal when optical paths of 50 meters or more are involved. However, the total angular and spatial spreading which can be experienced by an initially collimated pencil beam rarely exceeds 100 microradians and a meter or two, respectively.(1) Also, coherence distances are still on the order of centimeters (requiring only modest diversity of a coherent receiver), and no experimental evidence of pulse broadening exists, even down to picosecond lengths.(2,3) In contrast, particulate multiple scatter can induce dispersion in angle of arrival the order of tens of degrees, beam spreading in the hundreds of meters, degradation of spatial coherence down to lengths of microns or less, and multipath time spreading in the tens of microseconds.(4) Because of the magnitude of these larger effects, the mutual coherence function approach to channel characterization cannot be universally applied (we will shortly find it to be valid only over a finite range of scattering thicknesses), and additional mathematical techniques must be used to model optical propagation through these individual channels. In this chapter, we shall review the inherent and characterizing properties of the three basic components of the optical scatter channel: the atmosphere, the ocean, and the air/sea interface. A clear understanding of these building blocks must be possessed if one is to model satisfactorily the transfer of optical radiation through their individual and/or combined parts. Chapter 7 will describe how this information has been, and is currently, used to quantify energy propagation through the invididual and combined structures of this channel. Whenever possible, we have compared measured characteristics of the channel and its components with predictions from pertinent analytical or empirically devised models.

Keywords

Attenuation Coefficient Secchi Depth Inherent Property Cloud Type Extinction Efficiency 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    A. L. Buck, Effect of the atmosphere on laserbeam propagation, Appl. Opt. 6, 703–708 (1967).CrossRefGoogle Scholar
  2. 2.
    J. R. Kerr, P. J. Titterton, and C. M. Brown, Atmospheric distortion of short lasers, Appl. Opt. 8(11), -2233–2239 (1967).Google Scholar
  3. 3.
    Brookner, Atmospheric propagation and communication channel model for laser wavelengths, IEEE Trans. Commun. Technol. COM-18, 396–416 (1970).Google Scholar
  4. 4.
    E. A. Bucher, Computer simulation of light pulse propagation for communication through thick clouds, Appl. Opt. 12, 2391–2400 (1973).CrossRefGoogle Scholar
  5. 5.
    H. C. van de Hulst, Light Scattering by Small Particles, John Wiley and Sons, New York (1957).Google Scholar
  6. 6.
    M. Kerker, The Scattering of Light and Other Electromagnetic Radiation, Academic Press, New York (1969).Google Scholar
  7. 7.
    D. Deirmendjian, Electromagnetic Scattering on Spherical Polydispersion, Elsevier, New York (1969).Google Scholar
  8. 8.
    J. A. Stratton, Electromagnetic Theory, McGraw-Hill, New York (1941).MATHGoogle Scholar
  9. 9.
    M. Born and E. Wolf, Principles of Optics, Fourth Edition, Pergamon Press, New York (1970).Google Scholar
  10. 10.
    J. D. Jackson, Classical Electrodynamics, John Wiley and Sons, New York (1975), Chap. 6, 209–254.Google Scholar
  11. 11.
    S. Karp, A Test Plan for Determining the Feasibility of Optical Satellite Communications through Clouds at Visible Frequencies, Naval Ocean Systems Center Technical Note, TN279 (July 1, 1978 ).Google Scholar
  12. 12.
    G. W. Kattawar, Monte Carlo methods in radiative transfer, in: Multiple Light Scattering in Atmospheres, Oceans, Clouds and Snow, Institute for Atmospheric Optics and Remote Sensing, Short Course No. 420, Williamsburg, Virginia, December 4–8, 1978.Google Scholar
  13. 13.
    H. C. van de Hulst, Multiple Light Scattering in Atmospheres, Oceans, C.ouds and Snow. Institute for Atmospheric Optics and Remote Sensing, Short Course No. 420, Williamsburg, Virginia, December 4–8, 1978.Google Scholar
  14. 14.
    T. S. Chu and D. C. Hogg, Effects of precipitation on propagation at 0.63, 3.5 and 10.6 microns, Bell System Tech. 1. 47, 723–759 (1968).Google Scholar
  15. 15.
    W. S. Ross, W. P. Jaeger, J. Nakai, T. T. Nguyen, and J. H. Shapiro, Atmospheric optical propagation-an integrated approach, Opt. Eng. 21, 775–785 (1982).CrossRefGoogle Scholar
  16. 16.
    C. W. Fairall, K. L. Davidson, and G. E. Schacher, Meteorological models for optical properties in the marine atmospheric boundary layer, Opt. Eng. 21, 847–857 (1982).CrossRefGoogle Scholar
  17. 17.
    H. G. Hughes and J. H. Richter, Extinction coefficients calculated from aerosol size distributions measured in a marine environment, Proc. Soc. Photo-Opt. Instrum. Eng. 195, 39–45 (1979).Google Scholar
  18. 18.
    W. C. Wells, G. Gal, and M. W. Munn, Aerosol distribution in maritime air and predicted scattering coefficients in the infrared, Appl. Opt. 16, 654–659 (1977).CrossRefGoogle Scholar
  19. 19.
    E. A. Barnhardt and J. L. Streete, A method of predicting atmospheric aerosol scattering coefficients in the infrared, Appl. Opt. 9, 1337–1344 (1969).CrossRefGoogle Scholar
  20. 20.
    R. M. Lerner and A. E. Holland, The optical scatter channel, Proc. IEEE 58, 1547–1563 (1970).CrossRefGoogle Scholar
  21. 21.
    J. W. Fitzgerald, Approximate formulas for the equilibrium size of an aerosol particle as a function of its dry size and composition and the ambient relative humidity, J. Appl. Meteorol. 14, 1044–1049 (1975).CrossRefGoogle Scholar
  22. 22.
    C. Ciany, R. Farrell, and G. Saum, Laser Communications Climatology Study, McDonnell-Douglas Astronautics, Final Report, Contract No. N00014–78-C-0539 (August 31, 1979 ).Google Scholar
  23. 23.
    H. R. Gordon, R. C. Smith, and J. R. V. Zaneveld, Introduction to ocean optics, Proc. Soc. Photo-Opt. Instrum. Eng. 208, 14–55 (1980).Google Scholar
  24. 24.
    N. G. Jerlov, Marine Optics, Elsevier, Amsterdam (1976), p. 251.Google Scholar
  25. 25.
    A Morel, Optical properties of pure water and pure sea water, in: Optical Aspects of Oceanography (N. G. Jerlov and E. S. Nielsen, eds.), pp. 1–24, Academic Press, New York (1974).Google Scholar
  26. 26.
    P. Penndorf, On the Phenomenon of the Colored Sun, Air Force Cambridge Research Center, Technical Report No. 53–7 (1953).Google Scholar
  27. 27.
    J. R. Hodkinson, Light scattering and extinction by irregular particles larger than the wavelength, in: I.C.E.S. Electromagnetic Scattering (M. Kerker, ed.), Vol. 5, pp. 87–100 Pergamon Press, London (1963).Google Scholar
  28. 28.
    A. C. Holland and G. Gagne, The scattering of polarized light by polydisperse systems of irregular particles, Appl. Opt. 9, 1113–1121 (1970).CrossRefGoogle Scholar
  29. 29.
    T. J. Petzold, Volume Scattering Functions for Selected Ocean Waters, Scripps Institute of Oceanography, SIO Ref. 72–28 (1972).Google Scholar
  30. 30.
    S. P. Tucker, Measurements of the absolute volume scattering function for green light in southern California coastal waters, Ph.D. Dissertation, Oregon State University, Corvallis (1973).Google Scholar
  31. 31.
    R. W. Preisendorfer, Hydrologic Optics, Vol. V, Properties, U.S. Government Printing Office, Boulder, Colorado (1976).Google Scholar
  32. 32.
    J. G. Tyler and R. W. Preisendorfer, Transmission of energy within the sea, in: The Sea, (M. N. Hill ed.), Vol. 2, Interscience Publishers, New York (1962).Google Scholar
  33. 33.
    R. G. Driscoll, J. N. Martin, and S. Karp, OPSATCOM Field Measurements, Technical Document 490, Naval Electronics Laboratory Center (June 1, 1976 ).Google Scholar
  34. 34.
    D. B. Judd, Terms, definitions and symbols in reflectometry, J. Opt. Soc. Am. 57, 445–452 (1967).CrossRefGoogle Scholar
  35. 35.
    R. W. Austin, S. Q. Duntley, W. H. Wilson, C. F. Edgerton, and S. E. Moran, in: Ocean Color Analysis, Scripps Institution of Oceanography, SIO Ref. 74–10 (1974).Google Scholar
  36. 36.
    R. E. Davidson, D. R. Moore, and H. C. van de Hulst, The transfer of visible radiation through clouds, J. Atmos. Sci. 26, 1078–1087 (1968).Google Scholar
  37. 37.
    S. Twomey, Private communication.Google Scholar
  38. 38.
    J. E. Tyler, Radiance distribution as a function of depth in an underwater environment, Bull. Scripps Inst. Oceanog. 7, 363–412 (1960).Google Scholar
  39. 39.
    R. C. Smith and J. E. Tyler, Optical properties of clear natural waters, J. Opt. Soc. Amer. 57, 595–602 (1966).Google Scholar
  40. 40.
    J. G. Tyler and R. C. Smith, Measurement of Spectral Irradiance Underwater, Ocean Series, 1, Gordon and Breach Science Publishers, New York (1970).Google Scholar
  41. 41.
    A. Morel and L. Caloumanos, Mesures d’Éclairements Sous-marins Flux du Photons et Analyse Spectrale, Campagnes Hartmattan et Cancen II, 3e Parte, Présentation des Résultats, Rapport no. 11, Laboratoire d’Océanographie Physique, Villefranche-sur-Mer, France (1970).Google Scholar
  42. 42.
    A. Morel and L. Prieur, Analyse Spectrale des Coefficients d’Absorption et de Rétrodiffusion pour Diverses Régions Marines, Rapport No. 17, Laboratoire d’Océanographie Physique, Villefranche-sur-Mer, France (1975).Google Scholar
  43. 43.
    T. J. Petzold, Prediction of Ocean Water Reflectance Factor from “Water Type” or Diffuse Attenuation Coefficient, Science Applications, Inc., Interim Report No. 33 (Sept. 18, 1981 ).Google Scholar
  44. 44.
    R. W. Austin, Private communication.Google Scholar
  45. 45.
    R. W. Austin, Coastal zone color scanner radiometry, Proc. Soc. Photo-Opt. Instrum. Eng.: Ocean Optics VI 208, 170–177 (1980).CrossRefGoogle Scholar
  46. 46.
    R. W. Austin, Remote sensing of the diffuse attenuation coefficient of ocean water, in: Special Topics in Optical Propagation, AGARD Conference Proceedings No. 300, pp. 18–1–189, Technical Editing and Reproduction Ltd., London (1981).Google Scholar
  47. 47.
    J. E. Tyler, The Secchi disc, Limnology and Oceanography XIII, 1–6 (1960).Google Scholar
  48. 48.
    M. A. Frederick, An atlas of Secchi disc transparency measurements and Forel-Vle color codes for the oceans of the world, U.S. Naval Postgraduate masters thesis (Sept., 1970 ).Google Scholar
  49. 49.
    H. R. Gordon and A. W. Wouters, Some relationships between Secchi depth and inherent optical properties of natural waters, Appl. Opt. 17, 3341–3343 (1978).CrossRefGoogle Scholar
  50. 50.
    V. I. Man’Kovskty, Empirical formula for estimating the light attenuation coefficient in sea water, Oceanology: Methods and Instruments 18 (4), pp. 493–494 (1978).Google Scholar
  51. 51.
    H. R. Gordon, R. Brown, and M. M. Jacobs, Computed relationships between the inherent and apparent optical properties of a flat homogeneous ocean, Appl. Opt. 19, 417–427 (1975).Google Scholar
  52. 52.
    W. H. Wilson, Spreading of light in ocean water, Proc. Soc. Photo-Opt. Instrum. Eng.: Ocean Optics VI 208, 64–72 (1980).CrossRefGoogle Scholar
  53. 53.
    G. P. Sorenson, R. C. Honey, and J. R. Payne, Analysis of the Use of Airborne Laser Radar for Submarine Detection and Ranging, Stanford Research Institute, Report 55E3 (1966).Google Scholar
  54. 54.
    V. A. Timofeeva and F. I. Gorobetz, The relationship between the coefficient of extinction of collimated and diffuse fluxes of light, Izv. Akad. Nauk SSSR, Ser. Geofiz. 3, 291 (1967).Google Scholar

Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • Sherman Karp
    • 1
  • Robert M. Gagliardi
    • 2
  • Steven E. Moran
    • 3
  • Larry B. Stotts
    • 4
  1. 1.Lutronix, Inc.San DiegoUSA
  2. 2.University of Southern CaliforniaLos AngelesUSA
  3. 3.SAICSan DiegoUSA
  4. 4.DARPAArlingtonUSA

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