 This allowed the operator to pick out a single aircraft as long as they weren't in formation, but could not be used to directly guide the guns.In contrast, the 1.5 m wavelength of the new sets allowed an antenna of about the same size to feature eight dipoles, reducing the angle to about 1.5 degrees.Although this was of marginal capability in terms of directly aiming the guns, in July 1939 it was noticed that when the Army's 9.2-inch guns missed their targets, the splash of water caused by the shell would cause a brief but obvious return on the radar sets.