right|thumb|Johann Gabriel Doppelmayr.
Johann Gabriel Doppelmayr (27 September 1677 – 1 December 1750) was a German mathematician, astronomer, and cartographer. (His surname is also spelled Doppelmayer and Doppelmair.)
Professional life and publications
He was born in Nuremberg, the son of the merchant Johann Siegmund Doppelmayr. He entered the Aegidien-Gymnasium in Nuremberg in 1689, then the University of Altdorf in 1696. His studies included mathematics, physics, and jurisprudence. Later he continued his studies in Halle and graduated in 1698 with a dissertation on the Sun.
During studying at the University of Halle, he also learned French and Italian. After giving up his legal studies he then spent two years travelling and studying in Germany, Holland, and England, spending time at Utrecht, Leiden, Oxford, and London, during which time he learned to speak French, Italian, and English. He continued to study astronomy and learned to grind and figure his own telescope lenses.