wichita.edu
…Further observations revealed that I could view different expanses of Earth's surface at varying altitudes and stations. For instance, at an altitude of approximately 320 miles, the visual angle extended to about 20 degrees, corresponding to a horizontal span of roughly 1200 miles of Earth's surface. At 773 miles above, the visual angle increased to 30…
https://www.wichita.edu/academics/fairmount_las/geology/wparcell/Kircher/IterII/index.php