III.1. Basic concepts

This section of AMPLE enables one to make ephemeris calculations in various coordinate systems (spherical, rectangular) connected with different main planes (equator, ecliptic, horizon) and having origin in different points: geocenter, any point on the Earth surface, the Sun, any major planet, any minor planet. (The choice of some minor planet as a center gives possibility to find approaches of the minor planet with any set of major planets and minor planets. It is necessary to order the number of minor planet in Center, to select calculation of ephemeris of any set of objects in rectangular coordinates, and to introduce necessary restriction of distance from the object ordered as center of coordinate system.)

To start calculation one should specify object(s), coordinate system, interval of ephemeris and its step, format of output data and possible restrictions that can be imposed on them. These actions are performed by menu selection and by keyboard input of corresponding data into assigned fields.

It is usual to scan menu from top down. Making choice at each step restricts freedom of selecting menu items at subsequent steps. The application keeps track of the compatibility of specifications made in different items of menu. Some choices are found to be impossible. In such a case they are veiled from view.

All settings used in preceding run are preserved in memory and they are feasible for subsequent use with some modifications or without them. Retained or newly introduced information on task can be seen on entering Task description.

Sometimes alteration of some settings without proper alterations of other ones can lead to impermissible target. In such a situation a warning notice appears in Task description. Going through menu from top down user must change settings in such a way as to eliminate the incompatibility of initial data.

In the following table all the cases which correspond to inadmissible for AMPLE specifications are marked by sign –: