Comments on ´Position, velocity and acceleration estimates from the noisy radar measurements´

The recent paper by Ramachandra [1] deals with tracking in two dimensions by using essentially the equivalent of two one-dimensional tracking filters. This correspondence item points out a limitation to this in Reference 1. It also shows how the results given there and in three similar previous papers [2-4] can be expressed much more simply by means of some matrix transformation relationships, of which the authors do not appear to have been aware.