Ephemeris Data Files

This chapter describes the installation of Swiss Ephemeris data files.

Installation steps are

• Download the data files (see below)
• Open the configuration dialog, select the General Configuration/Ephemeris tab
• Click the button for ephemeris data files selection, choose the directory of the files

Astronomical Background

Standard calculation of the program is according to the built-in Moshier ephemeris. The ephemeris is quite good, but it is possible to increase the precision with the Swiss Ephemeris data files.

Precision of Moshier ephemeris is about 1 second of arc. The ephemeris covers the time interval from 3000 BC to 3000 AD.

Data files can be downloaded from Astrodienst Zürich. The data files have time intervals of 600 years each. Maximum time of validity is from 5401 BC to 5399 AD.

The URL of the download directory is ftp://ftp.astro.com/pub/swisseph/ephe/.

Types of Data Files

There are several different types of data files.

• Planetary data files - used for all planets Sun, .. Pluto (without Moon).
• Moon files - special files for the Moon
• Main asteroid files - used for planetoids Ceres, .. Vesta, Chiron and Pholus

All files are valid for 600 years. The table below summarizes the available files.

Time Range	Planetary File	Moon File	Asteroid File
5401 BC - 4802 BC	seplm54.se1	semom54.se1	seasm54.se1
4801 BC - 4202 BC	seplm48.se1	semom48.se1	seasm48.se1
4201 BC - 3602 BC	seplm42.se1	semom42.se1	seasm42.se1
3601 BC - 3002 BC	seplm36.se1	semom36.se1	seasm36.se1
3001 BC - 2402 BC	seplm30.se1	semom30.se1	seasm30.se1
2401 BC - 1802 BC	seplm24.se1	semom24.se1	seasm24.se1
1801 BC - 1202 BC	seplm18.se1	semom18.se1	seasm18.se1
1201 BC - 602 BC	seplm12.se1	semom12.se1	seasm12.se1
601 BC - 2 BC	seplm06.se1	semom06.se1	seasm06.se1
1 BC - 599 AD	sepl_00.se1	semo_00.se1	seas_00.se1
600 AD - 1199 AD	sepl_06.se1	semo_06.se1	seas_06.se1
1200 AD - 1799 AD	sepl_12.se1	semo_12.se1	seas_12.se1
1800 AD - 2399 AD	sepl_18.se1	semo_18.se1	seas_18.se1
2400 AD - 2999 AD	sepl_24.se1	semo_24.se1	seas_24.se1
3000 AD - 3599 AD	sepl_30.se1	semo_30.se1	seas_30.se1
3600 AD - 4199 AD	sepl_36.se1	semo_36.se1	seas_36.se1
4200 AD - 4799 AD	sepl_42.se1	semo_42.se1	seas_42.se1
4800 AD - 5399 AD	sepl_48.se1	semo_48.se1	seas_48.se1