also: グノモンとうえい
noun
A map projection where great circles are straight lines; used in navigation and seismology.
ノモン投影では、大圏航路が直線で表される。
In a gnomonic projection, great-circle routes are shown as straight lines.
地震の震源分布をノモン投影で図示した。
The distribution of earthquake epicenters was plotted using a gnomonic projection.
From English 'gnomonic projection', with the 'g' sometimes dropped in Japanese pronunciation.