Noise and time and frequency-a potpourri

Several sources of noise encountered in time- and frequency-related equipment are discussed. The noises can be characterized by their spectral type and mode of influence (e.g. additive or multiplicative). The noises have various consequences in processing equipment that can seriously affect performance. The spectral types of noise, the physical origins in various devices (where known), and the consequences of signal processing (i.e. frequency addition, subtraction, multiplication, and division) are reviewed. The effect of noises on the stability of oscillators and frequency standards is examined