Computer Programs for Sun and Moon Illuminance with Contingent Tables and Diagrams

摘要

There is an ever increasing need for quantitative information concerning everyday astronomical events as they affect the range of private, civil and military activities. The information most needed is usually one or a combination of the following: 1. rise and set times of the Sun and Moon, 2. beginning and ending times of twilight, 3. total number of daylight hours, 4. maximum height of the Sun or Moon above the horizon with corresponding time of occurrence, 5. at specific instants, the angular distance of the Sun or Moon from the horizon and from a cardinal direction, 6. the amount of natural light at a designated time of day or night. Despite the calculational complexities implied, it is possible not only to satisfy the needs for all such data in a straightforward way, but also to place appropriate tools for producing the data directly in the hands of those who need it. This publication is intended for a large number of people who have requirements for the type of data listed, but whose education has placed no special emphasis on astronomy. In what follows there are the means for calculating the needed information either by one of the self-contained computer routines provided, or by use of tables, diagrams (also included) and simple arithmetic.