Comparison of adaptive target-tracking algorithms for phased-array radar

The effects of incorporating a timevarying update time into three target-tracking algorithms based on the αβ- and αβγ-filters are presented and compared. The resulting performance figures are presented, these being the mean square errors, the mean update time and the mean number of updates. The update times are chosen according to the inverse of either the square root or cube root of the position residual. As expected, the αβγ-filter yields larger update times during the manoeuvre than those obtained with the αβ-filter, as the residuals obtained with the former filter are smaller during the manoeuvre. It is found that the best compromise between the number of updates and estimation errors is obtained when the update time is chosen according to the inverse of the square root of the residual when the αβ-filter is being used, and the inverse of the cube root of the residual when the αβγ-filter is being used. Finally, a discussion is presented as to how a combination of the αβ- and αβγ-filters can be made to track a target which executes manoeuvres.