Swiss Ephemeris

ZET have a Swiss Ephemeris module licensed at Astrodienst.

Main Swiss Ephemeris files, presented in ZET 7 Lite, are following:

• swdll32.dll - caclulation module, - this file should located either in main ZET 7 folder, or in system Windows directory.
• sepl_18.se1 - planets ephemeris files with date range from 1800 to 2399 years, this and next files should be located in [ZET]/Swiss folder.
• semo_18.se1 - Moon ephemeris file for same range,
• seas_18.se1 - Main asteroids ephemeris file (Ceres, Pallas, Juno, Vesta, Chiron, Pholus) for same range.

The description of the Swiss Ephemeris you can find at www.astro.com.

Here is a chapter about ephemeris files:

The core part of Swiss Ephemeris is a compression of the JPL-Ephemeris DE406.  Using a sophisticated mechanism, we succeeded in reducing JPL's 200 MB storage to only 18 MB. The agreement with DE406 is  within 1 milli-arcsecond (0.001”).  Since the inherent uncertainty of the JPL ephemeris for most of its time range is much greater, Swiss Ephemeris should be completely satisfying even for computations demanding very high accuracy.

The time range of the JPL ephemeris is 3000 BC to 3000 AD or 6000 years. We have extended this time range to 10'800 years, from 2 Jan 5401 BC to 31 Dec 5399. The details of this extension are described below in section 2.1.5.

Each Swiss Ephemeris file covers a period of 600 years; there are 18 planetary files, 18 Moon files and 18 main-asteroid files for the whole time range of 10'800 years.

The file names are as follows:

You can find these files at ftp://ftp.astro.ch/pub/swisseph/ephe/.

How to download and install addition asteroids files see at Catalog of Asteroids.

If you just have any astrology software with Swiss Ephemeris files, you may not copy them in Swiss folder, but specify a path to them (see General Settings).