a Norwegian cartographer and military officer. He was born in Arendal; the son of merchant Herman Frøchen Roosen and Johanne Dorthea Thestrup. He was a brother-in-law of Marcus Thrane. He headed Trondhjems Ingeniørdetachement from 1845 until his retirement in 1870. His cartographic works led to the publishment of several maps of Norway. In 1865, he published the book Om Skiløbningen, on the art of skiing.
