The physiological phenomena whereby a human eye retains perception of an image for a short time after the image is no longer visible. Phase A measure of the relative position of a signal relative to a reference expressed in degrees. Phase Distortion A distortion of the phase component of a signal. This occurs when the phase shift of an amplifier is not proportional to frequency over the design bandwidth. The number of picture elements resolved on a television picture screen.
More crisp pictures result as the number of picture elements is increased.
Polar Mount A dish mount that permits all satellites in the geosynchronous arc to be scanned with movement of only one axis. Polarisation A characteristic of the electromagnetic wave. Positive Picture Phase Positioning of the composite video signal so that the maximum point of the sync pulses is at zero voltage. The brightest illumination is caused by the most positive voltages. Preamplifier The first amplification stage.