using passive navigation aids external to the vehicle, e.g. markers, reflectors or magnetic means

Full Title

Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots > Control system inputs > Arrangements for determining position or orientation > using passive navigation aids external to the vehicle, e.g. markers, reflectors or magnetic means

Classification Context

Section:

PHYSICS

Class:

CONTROLLING; REGULATING

Subclass:

SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES