Comments on `The real time implementation of propagator bearing estimation algorithm by the use of a neural network´ by L. Fa-Long et al

In the above-titled paper (ibid., vol.17, p.320-5, Oct. 1992) the authors employ a propagator which they refer to as `the Marcos propagator´ and credit S. Marcos and B. Benidir (1990) with its introduction. It is pointed out that this same operator was mentioned for the first time in French by Jacques Munier (1987). In that paper, Munier states that S. Spitz defined the same operator in an unpublished paper. The commenter suggests that the operator be referred to as the `Munier propagator´ or the `Munier-Spitz propagator´