I will call this to be a translating system with a coordinate fix on the hull, somewhere on the hull, but not rotating, but parallel to the O X system that means, it is a steadily transmitting system; that means, if I call O X Y Z as inertial system I am going to call this, let me call this O dash, O dash, X dash, Y dash, Z dash as steadily translating system fixed with the body that means, the point O dash is fix on the body