A method and arrangement for controlling a position of a discharge spout (45) of a forage harvester (10) to distribute material into a container (18) of a transport vehicle (12) during material unloading comprising the steps of or means for:a. aligning an indicator (800) with an image of a predetermined location of the container (18) on a display (142), wherein the indicator (800) is in communication with the discharge spout (45)b. aligning the discharge spout (45) with the predetermined location of the container (18) based on alignment of the indicator (800) in step (a)c. capturing features of the container (18) in proximity of the predetermined location of the container (18)d. receiving GPS coordinates for the forage harvester (10) and the transport vehicle (12)e. computing a relative location of the front edge of the container (18) with respect to the forage harvester (45) based on the captured features of the predetermined location of the container (18)f. computing a relative location (X1) of the forage harvester (45) and the transport vehicle (12) based on their respective GPS coordinatesg. computing a relative location of the front edge of the container (18) to the transport vehicle (12) from the GPS coordinates of the transport vehicle (12) and the captured features of the front edge of the container (18) to form an offset (X2)h. receiving subsequent GPS coordinates of the forage harvester (45) and the transport vehicle (12)i. combining the subsequent GPS coordinates with the offset (X2) of the container (18) with respect to the transport vehicle (12) to calculate a new relative location (X1 + X2) of the front edge of the container (18) with respect to the forage harvester (45) andj. repeating steps h, and i until material unloading is terminated.
