How did Piri Reis manage to draw up an accurate map of the Antarctic?

Scientific expedition «Trails of Nomads» is on the highest and coldest continent of the Earth. What is the importance of the Kazakh expedition to the South Pole led by Sapar Iskakov? How did the Turkish navigator Piri Reis manage to draw up an accurate map of the Antarctic? What is the need to build a scientific station in this part of the planet?