Abstract

A comparison of reticle-produced amplitude- and frequency-modulated waves has been made. By calculating the power content of each component of the frequency spectrum of a modulated wave, the optimum values for the parameters of bandwidth and modulation index have been determined. It is shown that an FM system with a modulation index of 1.8 and a bandwidth encompassing only the first sideband pair exhibits the highest effective signal-to-noise ratio. Using these values of bandwidth and modulation index, the FM system exhibits a slight effective signal-to-noise superiority when compared with an AM system operating under similar conditions. The superiority of effective signal-to-noise ratio is lost if either the bandwidth or modulation index departs markedly from its optimum value. The modulation efficiency for various reticle-produced modulated waves has also been calculated.

© 1961 Optical Society of America

Comparison of Infrared Tracking Systems

Alan R. Gédance
J. Opt. Soc. Am. 51(10) 1127-1130 (1961)

Comparison of AM and FM Reticle Systems

Robert O’B. Carpenter
Appl. Opt. 2(3) 229-236 (1963)

Photoconductive Time Constants and Related Characteristics of p-Type Gold-Doped Germanium

T. P. Vogl, J. R. Hansen, and M. Garbuny
J. Opt. Soc. Am. 51(1) 70-75 (1961)

Eye’s Response at Flicker Fusion to Square-Wave Modulation of a Test Field Surrounded by a Large Steady Field of Equal Mean Luminance

H. de Lange Dzn
J. Opt. Soc. Am. 51(4) 415-421 (1961)

Visual Responses to Time-Dependent Stimuli.* II. Single-Channel Model of the Photopic Visual System

D. H. Kelly
J. Opt. Soc. Am. 51(7) 747-754 (1961)