The wireless operators' work was often carried out under heavy artillery fire in makeshift dug-outs. The artillery batteries were important targets and antennas were a lot less robust than the guns, hence prone to damage requiring immediate repair. As well as taking down and interpreting the numerous signals coming in from the aircraft, the operator had to communicate back to the aircraft by means of cloth strips laid out on the ground or a signalling lamp to give visual confirmation that the signals had been received. The wireless communication was one way as no receiver was mounted in the aircraft and the ground station could not transmit. Details from: