Tracking small unmanned aircraft systems (SUAS) becomes increasingly important with their increased use in populated areas. We propose an effective tracking solution for SUAS using a networked system of one-dimensional scanning radars. Tracking SUAS with a network of radar systems requires extrinsic calibration of each radar to a common frame. We provide a calibration solution using an orthogonal Procrustes formulation that associates radar measurements from the ground-mounted radar to real-time-kinematic Global Positioning System (RTK-GPS) data. Two variations of the calibration are presented, an online and batch processing method. Outdoor hardware experiments validate the capabilities of the radar network in tracking SUASs. The advantages and disadvantages of the two calibration methods are also illustrated with simulation and hardware tests.