At ancient times , people were navigated by means of sun , fixed stars , etc . , while currently the common navigation systems are astronomic navigation , inertial navigation and radio navigation 以前,人們主要利用太陽(yáng)、星星等自然天體?,F(xiàn)在人們利用的導(dǎo)航系統(tǒng)主要有:天文導(dǎo)航系統(tǒng)、慣性導(dǎo)航系統(tǒng)、無(wú)線電導(dǎo)航系統(tǒng)三大類。