Comments, with reply, on "Procedure for counting moving objects as they stop

In the above paper (see ibid., vol.IM-35, p.334-37, Sept. 1986), the author presents a novel procedure for estimating the number of persons arriving to wait for an elevator. The movements and stopping of objects are sensed by means of two Doppler radars. The amplitude responses obtained from the radars are made independent of distance by solving the equation of the family of curves for the location. Principles presented in the original paper are enhanced to provide a similar but more straightforward and computationally efficient method for compensating the nonlinear distance-dependence of the radar signals. The pair of equations is solved analytically. The analytical solution can easily be computed in real-time using either ROM tables for logarithmic and exponential functions or a particular coprocessor that can handle logarithms and exponential functions. No iteration is required; thus, the direct method is more efficient and accurate than the iteratively obtained approximation. >