1. A method for determining the position of at least one object in a navigation system of co-ordinates, wherein: a) at least one reference point or marker ( 4 ) is connected to said object ( 11 ) in a defined positional relationship; b) said position of said object ( 11 ) is detected in relation to a detection system of co-ordinates; c) said position of said at least one reference point ( 4 ) is detected in relation to said detection system of co-ordinates; d) said position of said at least one reference point ( 4 a ) is detected in a navigation system of co-ordinates; and e) said position of said object ( 11 ) in said navigation system of co-ordinates is determined from said position of said at least one reference point ( 4 a ) in said navigation system of co-ordinates and from the position of said object ( 11 ) relative to said at least one reference point ( 4 a ), as determined in steps b) and c).