In Germany, he visited Friedrich Bessel, Johann Franz Encke, and Heinrich Christian Schumacher and, in Paris, he called on François Arago. From there he also went to both Greenwich and Dublin, largely in pursuit of manufacturers of good chronographs. Back home he discussed with admiral Greig his impressions and ordered the equipment for the observatory. In his equipment there was a mercuric artificial horizon mirror. To exclude measurement failures it was possible to look with the telescope direct to the stars or indirect via the mercurial mirror. Knorre was member of the Royal Astronomical Society. He was married three times, first to Elisabeth of Dieterichs (m. 1829) who died just three years later, next to her younger sister Dorothea von Dieterichs (m. 1833) who died at the age of 37 after giving birth to 13 children, and lastly to Emilie Gavel (m. 1852) who survived him in death. Knorre had fifteen children who survived infancy, of which the best known was his fifth son, the astronomer Viktor Knorre. He moved to Berlin in 1862 to study astronomy. Knorre retired 1871 from the Directorship of the Observatory in Nikolajew and moved to Berlin to be with his son Viktor. He died there in 1883.