Inventors:
Louis W. Gaussa - Penn Township, Westmoreland County PA
Kingsley F. Graham - Murrysville PA
John B. Lipchak - Forest Hills PA
Lesley Greenberg - Monroeville PA
Assignee:
Westinghouse Electric Corp. - Pittsburgh PA
International Classification:
G21C 1700
Abstract:
In a method and apparatus for reducing the effects of frequency burst noise and noise spikes accompanying a random pulse signal, pulses with an amplitude above a high threshold or below a low threshold are eliminated, with the remaining pulses of intermediate amplitude being statistically filtered. The statistical filter compares the current pulse count rate signal to maximum and minimum statistical limits generated from the recent average value of the pulse count rate using Poisson statistics, and clamps the output to the limit which is exceeded. If the pulse count rate is between the statistical limits, it is used as the output pulse count rate signal. If the statistical limits are exceeded for a designated interval indicative of a true change in the pulse count rate, clamping of the output signal is overridden so that the true change in pulse count rate can be tracked. Statistical filtering is resumed when the current pulse count rate is again within the statistical limits.