Audit-Grade Accuracy

How RAstro achieves the highest accuracy in Vedic astronomical calculations

NASA JPL Ephemeris

We use the same DE440 ephemeris data that NASA uses for spacecraft navigation. Sub-arcsecond precision for planetary positions.

Deterministic Computation

Same inputs always produce identical outputs. Every calculation is reproducible and verifiable.

Full Provenance

Every response includes complete data lineage - kernel versions, ayanamsa values, and computation timestamps.

Data Sources

RAstro derives all astronomical calculations from NASA's Jet Propulsion Laboratory (JPL) ephemeris files:

DE440.bsp - Planetary ephemeris covering 1550-2650 CE with sub-arcsecond accuracy
naif0012.tls - Leap second kernel for precise time conversion
pck00011.tpc - Planetary constants (orientation, radii)

These are the same data files used by NASA for interplanetary mission planning. They represent the most accurate publicly available model of our solar system.

Calculation Method

Apparent Geocentric Positions

All calculations use apparent positions as seen from Earth's center, accounting for light-time correction and aberration.

Atmospheric Refraction

Sunrise and sunset times include standard atmospheric refraction correction (34 arcminutes at horizon).

Sidereal Conversion

Tropical to sidereal conversion uses your choice of ayanamsa system: Lahiri (default), Raman, or Krishnamurti.

Transition Precision

Tithi, nakshatra, and yoga end times are calculated using numerical root-finding to microsecond precision.

Validation

Planetary Positions

Within 0.01° of JPL Horizons system - validated against NASA's official ephemeris service.

Panchanga Elements

Cross-validated against traditional printed almanacs and DrikPanchang. Typically within 1-2 minutes for transition times.

Eclipse Predictions

Within 6 minutes of NASA eclipse predictions for contact times.

Open Source

RAstro's calculation engine is open source. You can inspect, verify, and audit every computation method.

View on GitHub