Aryabhata, a prominent astronomer and mathematician of ancient India, authored the "Surya Siddhanta", a significant treatise that greatly influenced the development of astronomy in India.

Aryabhata, in his treatise "Surya Siddhanta", put forth the revolutionary idea that the Earth rotates on its axis, challenging the prevailing geocentric model of the universe.

Ancient Indian astronomers employed a combination of written texts, oral tradition, and stone inscriptions to document and preserve their astronomical observations and knowledge.

The "Pancasiddhantika", authored by Varahamihira, provides comprehensive descriptions of various astronomical instruments and their applications, including sundials, astrolabes, and armillary spheres.

Temples and religious institutions played a crucial role in preserving and transmitting ancient Indian astronomical knowledge. They served as centers of astronomical study and observation, religious texts contained astronomical information, and astronomers were often associated with these institutions.

Brahmagupta, in his treatise "Brahma Sphuta Siddhanta", introduced a method for determining the position of the Moon based on its motion relative to fixed stars, known as the "graha-ganita" method.

Sanskrit was the primary language used by ancient Indian astronomers to record their observations and knowledge, as it was the language of scholarship and scientific discourse in ancient India.

Aryabhata, in his treatise "Surya Siddhanta", provided a method for calculating the time of sunrise and sunset based on the latitude and longitude of a location.

The "Lilavati" treatise, authored by Bhaskara II, was primarily intended to teach basic arithmetic and geometry, and was not focused on astronomy.

Aryabhata, in his treatise "Surya Siddhanta", provided a method for calculating the circumference of the Earth based on the duration of a lunar eclipse.

Ancient Indian astronomers employed a variety of methods to measure time, including sundials, water clocks, and sand clocks.

Aryabhata, in his treatise "Surya Siddhanta", introduced a method for determining the position of planets based on their motion relative to the Sun, known as the "graha-ganita" method.

The "Brihat Samhita" treatise, authored by Varahamihira, was primarily focused on predicting astrological events and making horoscopes, rather than explaining astronomical concepts or providing instructions for constructing instruments.

Aryabhata, in his treatise "Surya Siddhanta", provided a method for calculating the time of lunar and solar eclipses based on the motion of the Moon and the Sun.

The "Pancasiddhantika" treatise, authored by Varahamihira, was primarily intended to compare and contrast different astronomical systems and theories, rather than explaining concepts or providing instructions for constructing instruments.