Brahmagupta was a renowned Indian astronomer and mathematician who lived in the 7th century. He made significant contributions to the field of navigation, including developing methods for calculating the position of celestial bodies and the distance between two points on Earth.

Surya Siddhanta is an ancient Indian astronomical text that dates back to the 5th century. It contains valuable information on navigation, astronomy, and mathematics. The text is attributed to the astronomer and mathematician Aryabhata.

Vasco da Gama was a Portuguese explorer who is credited with discovering the sea route from India to East Africa in 1498. His voyage marked a significant milestone in the history of navigation and trade.

The primary purpose of the Indian Ocean trade routes established by Indian navigators was trade. These routes facilitated the exchange of goods, spices, and other commodities between India and various regions of the world, including East Africa, the Middle East, and Southeast Asia.

Aryabhata was an Indian astronomer and mathematician who lived in the 5th century. He is known for his accurate calculations of the Earth's circumference, which were remarkably close to modern estimates.

The primary instrument used by Indian navigators for celestial navigation was the astrolabe. This instrument allowed them to measure the altitude of celestial bodies above the horizon, which was essential for determining their latitude and longitude.

Zheng He was a Chinese explorer and navigator who lived in the 15th century. He is credited with establishing the first regular trade route between India and China through his extensive voyages to the Indian Ocean.

The primary motivation for Indian navigators to explore and establish trade routes across the Indian Ocean was economic opportunities. These routes allowed them to trade valuable commodities, such as spices, textiles, and precious metals, with other regions of the world.

Bhaskara II was an Indian astronomer and mathematician who lived in the 12th century. He is known for his accurate calculations of the Earth's diameter, which were remarkably close to modern estimates.

The primary purpose of the Indian Ocean trade routes established by Indian navigators was trade. These routes facilitated the exchange of goods, spices, and other commodities between India and various regions of the world, including East Africa, the Middle East, and Southeast Asia.

Aryabhata was an Indian astronomer and mathematician who lived in the 5th century. He is known for his accurate calculations of the Earth's circumference, which were remarkably close to modern estimates.

The primary instrument used by Indian navigators for celestial navigation was the astrolabe. This instrument allowed them to measure the altitude of celestial bodies above the horizon, which was essential for determining their latitude and longitude.

Zheng He was a Chinese explorer and navigator who lived in the 15th century. He is credited with establishing the first regular trade route between India and China through his extensive voyages to the Indian Ocean.

The primary motivation for Indian navigators to explore and establish trade routes across the Indian Ocean was economic opportunities. These routes allowed them to trade valuable commodities, such as spices, textiles, and precious metals, with other regions of the world.