Method of marking a line

A method of marking a line on a ground surface using a line marking apparatus including a body, a line marking head movable relative to the body, and a positioning system, comprising the steps of:

• providing a mathematical model that describes a line to be marked by the line marking head;
• the line marking head marking the line, based on calculations rendered by the mathematical model, as the line marking apparatus moves over the ground surface;
• the positioning system determining a succession of geographical locations, hereafter referred to as position fixes, as the line marking head marks the line;
• cumulatively updating the mathematical model in response to each successive position fix obtained by the positioning system as the line marking apparatus moves over the ground surface;
• and
• adjusting the position of the line marking head relative to the body, in dependence upon the updated mathematical model, in response to each update of the mathematical model.