Mahendra Dayashankar Gor Sūri

Mahendra Suri authored the Yantra-rāja (The King of Instruments, written in 1370 CE)—a Sanskrit work on the astrolabe, itself introduced in India during the reign of the 14th century Tughlaq dynasty ruler Firuz Shah Tughluq (1351–1388 CE). Suri seems to have been a Jain astronomer in the service of Firuz Shah Tughluq. The 182 verse Yantra-rāja mentions the astrolabe from the first chapter onwards, and also presents a fundamental formula along with a numerical table for drawing an astrolabe although the proof itself has not been detailed. Longitudes of 32 stars as well as their latitudes have also been mentioned. 

Mahendra Suri also explained the Gnomon, equatorial co-ordinates, and elliptical co-ordinates. The works of Mahendra Suri may have influenced later astronomers like Padmanābha (1423 CE)—author of the Yantra-rāja-adhikāra, the first chapter of his Yantra-kirnāvali. He was a pupil of Madana Suri. His father was Dayashankar and mother was Vimla. Dayashankar and Vimla had eight children, four sons and four daughters. Mahendra married a woman by the name of Urmila and had four daughters.