Engineering topics

Roach, F. E.

Publications and source records attributed to Roach, F. E..

At least 19 records

NASA NTRS1973

A photometric study of the counterglow from space.

Photometric observations of the region of the counterglow (Gegenschein) made from OSO-6 are examined. The observations were made during the September to October 1970 period when the counterglow was between the Milky Way arms at a relatively high (negative) galactic latitude. The lines of sight included a slice across the antisun region at an inclination of 48 degrees to the ecliptic. A comparison is made between the photometric gradients as measured from the spacecraft and similar gradients deduced from ground-based observations.

Roach, F. E.↗

NASA NTRS1973

A photometric perturbation of the counterglow.

An example of photometric variability of a counterglow region in the antisolar direction is discussed. A speculative interpretation of its significance leads to the suggestion that the weakened radiance of the counterglow may in this case be due to a dust cloud of scattering material in the general region of the earth-moon system.

Roach, F. E.↗

NASA NTRS1972

A photometric model of the zodiacal light.

An intercomparison of published photometric investigations of the zodiacal light and gegenschein is made, leading to a compilation of brightnesses over the entire sky in a reseau with 5-deg intervals. The results are given in absolute units. Several graphical representations illustrate the compilation.

Roach, F. E.↗

NASA NTRS1972

Observations of the diffuse galactic light.

Systematic observations during five nights were made with a field of 137 arc seconds at a fixed declination of 20 deg 42 min through one arm of the Milky Way over a range of right ascension from 257 to 336 deg. Corrections for zodiacal light, airglow, and integrated starlight leave a residual which is interpreted as the diffuse galactic light. The residual, plotted against galactic latitude, suggests that the diffuse light in the sample studied emanates from several discrete sources.

Roach, F. E.↗

NASA NTRS1972

Surface photometry of celestial sources from a space vehicle - Introduction and observational procedures.

Consideration of the possibility of studying diffuse celestial sources of relatively low surface brightness such as the Milky Way, zodiacal light, and gegenschein from above the earth's atmosphere with equipment flown in artificial satellites. The techniques used for this purpose are reviewed, and some of the difficulties encountered in daytime observations from satellites by the use of a special photometer and polarimeter flown in the orbiting skylab observatory, OSO-6, are cited.

Roach, F. E.↗

NASA NTRS1972

A comparison of surface brightness measurements from OAO-2 and OSO-6

A comparison of surface brightness measurements of the night sky from the OAO-2 and OSO-6 satellites with ground observations shows good agreement between the space experiments but a systematic error in the zero point of the ground observations, indicating an additional atmospheric source of radiation.

Roach, F. E.↗

NASA NTRS1971