Vedha is a Sanskrit word meaning observation of celestial
bodies. The word vedha in Sanskrit comes from vyadh meaning ‘to distribute’ for
studies.
There are two types of vedha: drishti vedha, meaning study
with naked eyes and yantra vedha, meaning study of planets, etc., using
instruments.
Vedha is done for acquiring knowledge of astronomy and
astrology. The place of vedha is called the observatory (vedha shala). The
rulers in India set up observatories from time to time and promoted the study of
astronomy.
The fifth chapter in Rig Veda contains the Sanskrit word
Turyia, meaning observations about the Sun. The basic text in astronomy,
Vedanga Jyotisha (1300 BCE), written by Lagadh, also refers to calculations of
planetary motions, reiterating the concept of Vedha.
Vedha yantras i.e., instruments in the observatories are
rashi valay, for calculation of rashis to be used in predictions in astrology;
shanku yantra for measurements and study of motions of planets; prakasa yantra
and yantra siromani for forecasting eclipses and calculating auspicious days;
and gola yantra for measuring celestial coordinates.
Bhaskaracharya, the
astronomer and mathematician of the 13th century AD has described
these instruments.
Bibliography
Ancient Indian Mathematics and Vedha (1947) by L V Gurjar published
by Continental Book Service; Pune.
Encyclopedia of Hinduism Volume XI – page 261 - IHRF