Born in 1745 in Japan

Ino Tadataka was the late-Edo-period surveyor whose maps transformed Japan's understanding of its own territory. Born in 1745 in what is now Chiba Prefecture, he was adopted into the wealthy Ino merchant family at seventeen and built their sake-brewing and rice-trading business into one of the region's largest fortunes.

At fifty he handed the business to his son and moved to Edo to study astronomy under Takahashi Yoshitoki, the shogunate's official astronomer. Yoshitoki was nineteen years younger, yet Ino approached him with complete humility. Under Yoshitoki he mastered celestial observation and surveying mathematics, developing an ambition to determine the length of one degree of latitude through direct measurement.

In 1800, aged fifty-six, he received shogunal permission to survey the coastline of Ezo, modern Hokkaido. This first expedition proved his methods and earned official backing. Over the next seventeen years he led ten survey expeditions covering Japan's entire coastline and major roads. His total walking distance approached forty thousand kilometres, equivalent to one circuit of the earth.

His method combined traverse surveying with nightly astronomical fixes: compass bearings and chain measurements gave shape to the coast, while latitude observations from stars provided absolute positioning.

Ino died in 1818 at seventy-three without seeing the finished work. His disciples completed the Dai Nihon Enkai Yochi Zenzu in 1821: 214 sheets covering every coastline, whose outlines match modern satellite surveys with remarkable fidelity. The maps served as Japan's official cartographic base well into the Meiji era and laid the foundation for the country's modern triangulation surveys.