e cause. When the sampling rate interferes with the frequency of program material, aliasing takes the form of artifact frequencies known as sidebands. Spectral aliasing is caused by interference between two frequencies such as the luminance and chrominance signals and appears as herringbone patterns, wavy lines where straight lines should be, and loss of color fidelity. Temporal aliasing is caused when information is lost between line or field scans. It appears when a video camera is focused on a CRT. The lack of scanning synchronization produces an annoying flicker on the receiving device's screen. amplifier A device that receives an input signal in wave form (analog) and gives a magnified signal as an output. amplify To increase the magnitude of a voltage or a waveform in order to increase the strength of the signal. amplitude The magnitude of a waveform or voltage. Greater amplitude results when waves are set in motion with greater force. The term amplitude is also used to describe the strength of a signal. amplitude modulation AM. A method of changing a signal by varying its height or amplitude in order to superimpose it on a carrier wave. Used to impress radio waves (audio or video) onto a carrier in analog transmissions. analog Representations of numerical values by physical variables such as voltage and amplitude. Analog signals are continuously varying; indeed, depending on the precision with which they are sampled/measured, they can vary infinitely. By this we mean that each sample can produce a value that corresponds to the unique magnitude of the variable. An analog signal is one that uses electrical Glossary of Terms transmission methods to duplicate an original waveform, and thereby capture and convey these unique magnitudes. analog transmission A method of sending signals whereby the transmitted signal is analogous to the original signal. Sending a stream of continuously varying electrical waves represents the original sine wave. animation The process used to link a series of still images to create 