Abstract

With a recording photometer of photopic sensitivity, measurements were made of many points in the sky during twilight for solar altitudes H=+5° to −15° for clear air and no clouds at two stations, one in Maryland, altitude 30 meters, and one on Sacramento Peak, New Mexico, altitude 2800 meters. The sky polarization on the meridian through the sun, and the illumination on a plane at various orientations exposed to the sky, were also recorded. For H from about −3° to −11° the entire sky changed in brightness at about the same rate of a factor of 10 for each 2° change in H. Except at the horizon the Sacramento Peak sky was about 23 to 12 as bright as the Maryland sky because of clearer air; at the horizon the two were about the same. At Sacramento Peak the ratio of the polarized components reached a minimum of about 0.06 at the zenith for H=−3°.

© 1952 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. R. A. Richardson and E. O. Hulburt, Geophys. Res. 54, 215–227 (1949).
    [CrossRef]
  2. R. Tousey and E. O. Hulburt, J. Opt. Soc. Am. 37, 78–92 (1947).
    [CrossRef]
  3. D. M. Packer and C. Lock, J. Opt. Soc. Am. 41, 473–478 (1951).
    [CrossRef]
  4. E. O. Hulburt, J. Opt. Soc. Am. 39, 211–215 (1949), and four brief papers in Trans. Amer. Geophys. Un. 31, 539–548 (1950).
    [CrossRef]
  5. R. A. Richardson and E. O. Hulburt, Geophys. Res. 54, 229–238 (1949).
    [CrossRef]
  6. W. S. Plymale, Rev. Sci. Instr. 18, 535–539 (1947).
    [CrossRef]

1951 (1)

1949 (3)

E. O. Hulburt, J. Opt. Soc. Am. 39, 211–215 (1949), and four brief papers in Trans. Amer. Geophys. Un. 31, 539–548 (1950).
[CrossRef]

R. A. Richardson and E. O. Hulburt, Geophys. Res. 54, 215–227 (1949).
[CrossRef]

R. A. Richardson and E. O. Hulburt, Geophys. Res. 54, 229–238 (1949).
[CrossRef]

1947 (2)

Hulburt, E. O.

Lock, C.

Packer, D. M.

Plymale, W. S.

W. S. Plymale, Rev. Sci. Instr. 18, 535–539 (1947).
[CrossRef]

Richardson, R. A.

R. A. Richardson and E. O. Hulburt, Geophys. Res. 54, 229–238 (1949).
[CrossRef]

R. A. Richardson and E. O. Hulburt, Geophys. Res. 54, 215–227 (1949).
[CrossRef]

Tousey, R.

Geophys. Res. (2)

R. A. Richardson and E. O. Hulburt, Geophys. Res. 54, 215–227 (1949).
[CrossRef]

R. A. Richardson and E. O. Hulburt, Geophys. Res. 54, 229–238 (1949).
[CrossRef]

J. Opt. Soc. Am. (3)

Rev. Sci. Instr. (1)

W. S. Plymale, Rev. Sci. Instr. 18, 535–539 (1947).
[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 (3)

Fig. 1
Fig. 1

Zenith sky brightness values at Sacramento Peak.

Fig. 2
Fig. 2

Sky brightness values for Maryland.

Fig. 3
Fig. 3

Polarization of sky on meridian through sun at Sacramento Peak during evening twilight.

Tables (3)

Tables Icon

Table I Twilight sky brightness B candles per square foot at Sacramento Peak, New Mexico, altitude 2800 meters.

Tables Icon

Table II Twilight sky brightness B candles per square foot in Maryland, altitude 30 meters.

Tables Icon

Table III Illumination E foot candles upon a flat surface during twilight at Sacramento Peak, New Mexico, altitude 2800 meters.

Equations (2)

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

B = B + B .
ρ = B / B .