Treatise on the Five Astronomical Canons, PS, the Pancha Siddhantika by Varaha Mihira  

The Five Canons are  

Surya Siddhanta

Pitamaha Siddhanta

Lomasa Siddhanta

Paulasa Siddhanta

Vasishta Siddhanta  

 

Siddhanta Sastra means the Science of Astronomy and nothing else. Some scholars have mistranslated it as Doctrine or Theory. Similarly,  Vedanta has also been mistranslated. Vedanta means transcendental Knowledge, nothing else.  

Western scholars believe that there are  elements of Hellenistic Astronomy in Lomasa & Paulasa  Siddhantas. They say these two Siddhantas  are borrowed from The Doctrine of the Romans and the  Doctrine of Paulose, the Greek. This idea is pooh poohed by Indian scholars.

Written by Latha Deva, the SS , Surya Siddhanta, is one of the earliest books. It travelled wide from India to Spain and Baghdad. The Caliph ordered his scholars to translate SS ad this glorious book inspired European Astronomy and space sciences,


The first mathematical book, Brahma Sphuta Siddhanta, written by Brahmagupta, dealt with trignometric functions and was translated into Arabic as As Sind Hind.


The Aryabhateeyam of Arabhata was translated as Al Arjabhat and the Arabs got an insight into Mathematics, in Jyamiti, Geometry and Trikonamiti, Trignometry !


The Magnificent Hindu Geometrical Model



Computation can be from any of the Three Hindu Zero Points of the Ecliptic Ė The Tropical Zero Point, Sayana Meshadi, the Sidereal Zero Point, the Nirayana Meshadi and the Chaitradi, the Luni-Solar Zero Point.


Anomaly was defined as the angle between position ( of the planet ) & perihelion. Indian Astronomy computes both Sheeghra & Manda Anomalies.


What are Sheeghra & Manda Anomalies ?


Manda means slow and Mandoccha means Aphelion, implying the 2nd Law of Planetary Motion of Kepler, that all planets move slower at Aphelion, the planetís farthest point from the Sun.


Sheeghra means fast and Sheeghrocha means Perihelion, implying the 2nd Law of Planetary Moion of Kepler, that all planets move faster at Perihelion, the planetís nearest point to the Sun.


Manda refers to the Heliocentric Coordinate System and Sheeghra refers to the Geocentric Coordinate System.

In Greek, peri means near, ap ameans away and Helion is Sun. Helios is derived from the Sanskrit Heli, Heli Surya, Chandrama Sheeta Rashmi.