Ephemeris

The longitudes of planets are given as mean geocentric longitudes for the mean equinox of date (EOD) (movable astrology) or for the reference equinox of zero date (fixed astrology).
Correction UT-ET is taken into account.

Remark: In previous version of Proastro it was necessary to translate UNIX.406 or other JPL binaries from "big endian" to "little endian"
This stage is not required any more, translation "big endian" to "little endian" is automatically done, if needed.

Performances:
The best performances are obtained with ephemeris DE406
who only need file of about 200 Mb.
Low precision ephemeris are less fast than DE406 but does not need the binary file DE406.
DE431 must be used for astronomical charts in far past but asks a big file of 2.7 Go.
However performances are little affected in comparison with DE406.

To compare with the ephemerides in Proastro, you have two websites:

The precision, for 3000 B.C. is about ten seconds of arc for the longitudes of the planets, about 1 minute of arc for the Moon and a few arc minutes for Pluto (dwarf planet :))

See also:

Bibliographie