Abstract

The ratio of the amounts of scattered and direct radiation received from a 4π source has been measured in the San Francisco Bay Area for source-receiver distances of 1.18, 4.33, 6.79, 9.81, and 14.37 miles. A large flashlamp surrounded by a frosted globe was used as the source. The receiver consisted of any one of five combinations of Wratten fiters and photomultiplier tubes having peak responses at 0.40, 0.50, 0.70, 0.83, and 0.90 μ and feeding into an oscilloscope, the screen of which was photographed. A device for controlling the field of view of the receiver allowed choice of fields of view from 4 degrees to 58.33 degrees half-angle, and an occulter allowed the direct radiation to be blocked out if desired. It has been found that for a given field of view the ratio of scattered to direct radiation received from such a source under no overcast conditions is greater the shorter the wavelength and that for source-receiver distances of up to about 7 miles this ratio is approximately proportional to the optical thickness (path length times attenuation coefficient) of the path. For the source-receiver distances greater than 7 miles and a given attenuation coefficient and field of view, the ratio in question has been found to decrease slowly with increasing distance.

© 1959 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. H. S. Stewart and J. A. Curcio, J. Opt. Soc. Am. 42, 801 (1952).
    [Crossref]
  2. R. G. Eldridge and J. C. Johnson, J. Opt. Soc. Am. 48, 463 (1958).
    [Crossref]
  3. Mathew G. Gibbons, J. Opt. Soc. Am. 48, 550 (1958).
    [Crossref]
  4. Mathew G. Gibbons, J. Opt. Soc. Am. 47, 1056 (1957).
  5. Personal communication from H. M. Schmies, PhotoLamp Planning, General Electric Company, Nela Park, Cleveland 12, Ohio.
  6. Harold E. Edgerton, PSA Journal 13, 437 (1947).
  7. F. E. Carlson and D. A. Pritchard, Illum. Eng. 17, 235 (1947).
  8. H. N. Olsen and W. S. Huxford, J. Soc. Motion Picture Engrs. 55, 285 (1950).
  9. J. M. Waldram, Quart. J. Roy. Meteorol. Soc. 71, 319 (1945).
    [Crossref]

1958 (2)

1957 (1)

Mathew G. Gibbons, J. Opt. Soc. Am. 47, 1056 (1957).

1952 (1)

1950 (1)

H. N. Olsen and W. S. Huxford, J. Soc. Motion Picture Engrs. 55, 285 (1950).

1947 (2)

Harold E. Edgerton, PSA Journal 13, 437 (1947).

F. E. Carlson and D. A. Pritchard, Illum. Eng. 17, 235 (1947).

1945 (1)

J. M. Waldram, Quart. J. Roy. Meteorol. Soc. 71, 319 (1945).
[Crossref]

Carlson, F. E.

F. E. Carlson and D. A. Pritchard, Illum. Eng. 17, 235 (1947).

Curcio, J. A.

Edgerton, Harold E.

Harold E. Edgerton, PSA Journal 13, 437 (1947).

Eldridge, R. G.

Gibbons, Mathew G.

Mathew G. Gibbons, J. Opt. Soc. Am. 48, 550 (1958).
[Crossref]

Mathew G. Gibbons, J. Opt. Soc. Am. 47, 1056 (1957).

Huxford, W. S.

H. N. Olsen and W. S. Huxford, J. Soc. Motion Picture Engrs. 55, 285 (1950).

Johnson, J. C.

Olsen, H. N.

H. N. Olsen and W. S. Huxford, J. Soc. Motion Picture Engrs. 55, 285 (1950).

Pritchard, D. A.

F. E. Carlson and D. A. Pritchard, Illum. Eng. 17, 235 (1947).

Schmies, H. M.

Personal communication from H. M. Schmies, PhotoLamp Planning, General Electric Company, Nela Park, Cleveland 12, Ohio.

Stewart, H. S.

Waldram, J. M.

J. M. Waldram, Quart. J. Roy. Meteorol. Soc. 71, 319 (1945).
[Crossref]

Illum. Eng. (1)

F. E. Carlson and D. A. Pritchard, Illum. Eng. 17, 235 (1947).

J. Opt. Soc. Am. (4)

J. Soc. Motion Picture Engrs. (1)

H. N. Olsen and W. S. Huxford, J. Soc. Motion Picture Engrs. 55, 285 (1950).

PSA Journal (1)

Harold E. Edgerton, PSA Journal 13, 437 (1947).

Quart. J. Roy. Meteorol. Soc. (1)

J. M. Waldram, Quart. J. Roy. Meteorol. Soc. 71, 319 (1945).
[Crossref]

Other (1)

Personal communication from H. M. Schmies, PhotoLamp Planning, General Electric Company, Nela Park, Cleveland 12, Ohio.

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 (13)

F. 1
F. 1

Photograph of the source.

F. 2
F. 2

Relative output intensity of the source as a function of altitude angle.

F. 3
F. 3

Schematic diagram of the receiving apparatus.

F. 4
F. 4

Map of the source and receiver locations used in taking data.

F. 5
F. 5

Multiple exposure taken at the 4.33-mile receiver location. See text.

F. 6
F. 6

Multiple exposure taken 8 ft from the source. Seven successive flashes are shown.

F. 7
F. 7

Typical plot of peak signal at the receiver (mv developed across a 10K resistor in the anode circuit of the photomultiplier) vs field of view of the receiver for radiation of 0.7-μ wavelength and meteorological conditions as specified in the text. The triangles correspond to direct plus scattered radiation (occulter not in use), and the circles correspond to scattered radiation only (occulter in use).

F. 8
F. 8

Ratio R of scattered radiation to direct radiation as a function of field of view for the data shown in Fig. 7.

F. 9
F. 9

Dependence of R, the ratio of scattered radiation received to direct radiation received, on field of view of the receiver for several wavelengths when the source-receiver distance is 6.79 miles. See text for meteorological conditions. The number adjacent to each curve gives the wavelength in microns to which the curve corresponds.

F. 10
F. 10

Dependence of R, the ratio of scattered radiation received to direct radiation received, on the source-receiver distance for radiation of 0.7-μ wavelength and meteorological conditions as specified in the text. Values actually given for R are average values for a field of view of half-angle 58.33°.

F. 11
F. 11

Dependence of Tu/Tc, or R90+1, on Tc radiation of wavelength 0.7 μ and no-overcast conditions. See text for explanation of circles and triangles.

F. 12
F. 12

Dependence of Tu/Tc, or R90+1, on Tc for radiation of wavelength 0.9 μ and no-overcast conditions. See text for explanation of circles and triangles.

F. 13
F. 13

Dependence of Tu/Tc, or R90+1, on Tc for radiation of various wavelengths and no-overcast conditions. The dashed curve represents the predicted dependence of Tu/Tc on Tc for “white light.” The number adjacent to each curve gives the wavelength in microns to which the curve corresponds. For explanation of linear scale along top edge, see text.

Equations (5)

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

R 90 1.07 m R 90 1.25 m R 58.3 .
T u = T c ( 1 + 0.74 σ D ) .
R 90 D / V
R 90 1 / V
I c = J 0 e σ D D 2 = J 0 T c D 2 ,