Ephemeris Data Files

This chapter describes the installation of Swiss Ephemeris data files.

Installation is simple

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.

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