Technical documentation, mathematical proofs, and high-precision planetary ephemeris verification (JPL DE431 / Swiss Ephemeris / VSOP87) for sidereal and tropical astronomical computation. Interactive web implementations are hosted at AstrologyCalc.com.
Full accuracy comparison of JPL DE431, Swiss Ephemeris, and VSOP87 planetary longitudes with Lahiri Chitrapaksha Ayanamsa formulas.
Sub-arcsecond D1 Rashi and D9 Navamsha computation with exact spherical trigonometry horizon ascendant equations.
Deterministic lunar mansion (Nakshatra) progression across 9 planetary periods down to Prana-antardasha.
| Module / Algorithm | Mathematical Basis | Production Reference |
|---|---|---|
| Global Ephemeris Suite | JPL DE431 + IAU 2006 Precession + True Chitrapaksha | https://astrologycalc.com/ |
| Planetary Periods (Vimshottari) | 120-year cycle from Moon's exact 800' arc-minute Nakshatra traversal | Planetary Periods Calculator |
| Natal Chart (D1 & D9 Navamsha) | Ecliptic longitude λsid = (λtrop − Ayanamsa) mod 360° | https://astrologycalc.com/birth-chart-calculator/ |
| Horizon Ascendant (Lagna) | tan(λAsc) = cos(RAMC) / [−sin(RAMC)cos(ε) − tan(φ)sin(ε)] | Rising Sign & Ascendant Calculator |
| 22 Arcana Octagram Matrix | Base-22 modular arithmetic over diagonal & cardinal octagram nodes | https://astrologycalc.com/destiny-matrix-calculator/ |
| Five-Limb Lunar Almanac | Tithi (Δλ/12°), Nakshatra (λMoon/13°20'), Yoga, Karana, Vara | https://astrologycalc.com/lunar-calendar-panchanga/ |