Accession Number : AD0622440

Title :   DATA FOR THE CALCULATION OF TWILIGHT OBSERVATION PROGRAMMES.

Descriptive Note : Scientific rept.,

Corporate Author : SASKATCHEWAN UNIV SASKATOON DEPT OF PHYSICS

Personal Author(s) : Jones,A. Vallance

Report Date : MAY 1965

Pagination or Media Count : 21

Abstract : A general solution is given to the problem of constructing twilight programmes so that the direction of observation may intersect the boundary between dark and illuminated regions of the atmosphere at a specified height above the surface of the earth. Atmospheric refraction and absorption and the angular extent of the sun are neglected. These quantities must be taken into account separately. Curves giving the results of calculations from the twilight equations are reproduced. These curves are sufficient for the construction of twilight programmes for heights between 30 and 560 km. (Author)

Descriptors :   (*TWILIGHT, ANGLE OF ARRIVAL), (*SKY BRIGHTNESS, TWILIGHT), (*SOLAR RADIATION, TWILIGHT), (*ATMOSPHERES, OPTICAL PROPERTIES), SUN, LIGHT TRANSMISSION, REFRACTION, ABSORPTION, OPTICS, BOUNDARY VALUE PROBLEMS, CELESTIAL MECHANICS, MATHEMATICAL PROGRAMMING

Distribution Statement : APPROVED FOR PUBLIC RELEASE