Instantaneous parameter measuring receiver

Abstract

A method and apparatus for processing the log video output of a receiver that can measure multiple time overlapped pulses on a nearly instantaneous basis. The receiver measures frequency, pulse modulation, time of arrival, amplitude, pulse width and phase difference when simultaneous pulses are present. To detect pulse parameters a given voltage threshold must be exceeded and M out of the last N data samples must fall within a given voltage window that is above the threshold voltage. Pulse detection is initiated by establishing a dynamic noise threshold that is above the random noise level. When a pulse arrives, the value of the amplitude samples are measured and when the successive differences between the amplitude samples are small enough then a pulse presence is declared. Following detection of a pulse, amplitude samples are continuously taken and processed to detect the end of the pulse or a pulse-on-pulse condition. A pulse-on-pulse condition is detected when the difference between successive amplitude samples again starts to increase after initially stabilizing. As soon as M out of the last N amplitude samples fall within a predetermined voltage window then the second pulse has stabilized. On the trailing edge of the second pulse, the successive differences between amplitude samples become comparatively large and fall outside of the predetermined amplitude window indicating termination of the second pulse. By using this method, the receiver can determine when the leading edge of a pulse occurs, when the pulse is stable, when an additional pulse is encountered and when the pulse terminates.