Astronomi di India pada awalnya terikat dengan agama. <ref name=Sarma-Ast-Ind>Sarma (2008), ''Astronomy in India''</ref> Kitab [[Veda]], kitab penting agama Hindu, adalah tulisan pertama yang menyentuh perihal astronomi. <ref name=Sarma-Ast-Ind/> Seperti ulasan Sharma (2008): “Kitab [[Rigveda]] ada membuat spekulasi tentang penciptaan alam semesta dari tiada, dan susun letaknya, tentang [[Bumi]] yang bulat dan mampu menyokong beratnya sendiri, dan tentang setahun mempunyai 360 hari dibahagikan kepada 12 bahagian dengan 30 hari satu bahagian, dan kewujudan bulan-bulan interkalari (bulan dengan hari tambahan, seperti hari ke-29 bulan Februari dalam kalendar moden).” <ref name=Sarma-Ast-Ind/> Kaitan astronomi India dengan agama dibincangkan lebih lanjut [[Astronomi_India#Hubungan_dengan_agama|dibawah]].
The [[cardinal directions]] are found in the ''[[Shulba Sutras|Śulbasūtra]]'' (1st millennium BCE), a treatise containing mathematical applications used for altar construction.<ref name=abraham08/> Mathematics and astronomical instruments were employed to calculate time after sunlight, daylight periods, computation of sunrise, computation of sunset, and general measurement of time. Ōhashi (1993) states that ''[[Jyotiṣa|{{IAST|Jyotiṣa Vedānga}}]]'' astronomy gained a foothold between the 6th and the 4th centuries BCE.The common era saw the presence of numerous ''Siddhāntas'', out of which the ''[[Surya Siddhanta|Surya-siddhānta]]'' was particularly notable.<ref name=Klostermaier03/> Both the ''[[Yavanajataka]]'' and ''[[Romaka Siddhanta|Romaka Siddhānta]]'' confirm that Indian and western astronomical sciences had been a part of a global scientific discourse (given in the [[Indian_astronomy#Global_discourse|section below]]).
The ''[[Pancha-Siddhantika|Pañcasiddhāntikā]]'' (Varahimira, 505 CE) approximates the method for determination of the meridian direction from any three positions of the shadow using Gnomon.<ref name=abraham08/> By the time of [[Aryabhata|Aryabhata I]] the motion of planets was treated to be elliptical rather than circular.<ref name=Hayashi08Aryabhata/> Other topics included definitions of different units of time, eccentric models of planetary motion, epicyclic models of planetary motion, and planetary longitude corrections for various terrestrial locations.<ref name=Hayashi08Aryabhata/>
