1.3 Ephemeris
This tab contains several options for calculation.
Left Side
Custom Ayanamsa
These options can be used to configure custom Ayanamsa.Standard configuration of custom Ayanamsa is based upon a reference value at a given date (normally Jan 01 1990 = 2415020.5).
- Date t0 - reference date for Ayanamsa. Format is julian date.
- Ayanamsa at t0 - value at the date t0. Format of this field is double.
Advanced Cusom Ayanamsa Configuration
The constant period can be used to change the speed of vernal point movement.Default button: the built-in default values will be set. These values are based upon the built-in values of Lahiri Ayanamsa.
Caution: changes of these parameters can cause major calculation errors!
Remarks on Ayanamsa can be found in the Ayanamsa Section on this site.
Sunrise and Sunset
These options take effect for special Lagnas, Kala Velas and Hora calculation. The difference between the option will be about several minutes of time.Reference Point
Whether the center or the border of the disk shall be in the horizon at sunrise/sunset time.Use Refraction
Refraction is an optical phenomenon that is based upon the curvature of the sunlight in the atmosphere. Refraction will be taken into account if you check this option (apparent position).Right Side
Path for Ephemeris Data Files
Ephemeris data files can be used to increase the precision of the built-in default ephemeris.A detailed instruction for installation of these data files can be found in the section on Installation of Swiss Ephemeris Data Files .
Calculation
Caution: calculation options are very sensitive parameters!You should not change these parameters if you are not sure what you do!
Calculation options are described in detail at the Calculation Section.
The default button can be used to reset the values to the built-in defaults.