Track fusion of legacy radars using weighted averages

Abstract

In air defense systems, multiple radars with overlapping area of coverage are deployed for surveillance and tracking of aircraft. In such a situation, multiple tracks on the same target may appear. The problem of determining whether two tracks have originated from the same target is termed as Track-to-Track Association (T2TA). This process is followed by a Track-to-Track Fusion (T2TF) process which is done to fuse the tracks of multiple radars. Many multiple radar systems employ centralized T2TA and T2TF which takes place in a fusion center while the radars and their trackers are remotely located from the fusion center. Ideally, the radar trackers must supply target state estimates as well as the covariance and cross-covariance to the fusion center for optimal T2TA and T2TF. However, in case of legacy radars, only the target state estimates are provided to the fusion center. We propose a suboptimal but simple-to-implement technique based on weighted averages for T2TA and T2TF of legacy tracks. In the proposed technique, weighted averages are based on the reliability of the radar, track quality and deviation of target trajectory estimate from its smoothed value.