IX.1. Basic concepts

Present section of AMPLE enables one to obtain information on observatories engaged in observations of minor planets and to add new data to their catalogue incorporated into the package. As a basis of that is taken the catalog of observatories supported by the Minor Planet Center (Cambridge, USA). Each entry generally contains:

— observatory code

— east longitude of observatory expressed in degrees

— projections of the geocentric radius-vector of observatory on the Earth equatorial plane and on the Earth rotation axis, dxy and dz, correspondingly; both quantities are expressed in parts of the equatorial radius of the Earth taken as 6378.137 km; they are known as parallax constants

— observatory name (up to 50 symbols)

The observatory code is a string that contains three symbols, the first one being digit or letter, the second and the third ones being digits. In the code letter A stands for number 10, B stands for number 11, and so on. So, code B47 means number 1147.

User has possibility to select observatory by code or by name, to edit content of catalog, to calculate parallax constants of some observatory (some place on the Earth) depending on its geographical (geodesic) latitude and height above the sea level, and to solve reverse problem — to calculate latitude of place and height above the sea level depending on the values of its parallax constants.

To gain access to these options select Observatories item in menu bar and then select corresponding item in drop-down menu.