Recent Advancements in Basic Radar Range Calculation Technique

A procedure for radar range calculation is described, reflecting current knowledge of the effects of external natural noise sources, atmospheric-absorption losses, and the refractive effect of the normal atmosphere. The range equation is presented in terms of explicitly defined and readily evaluated quantities. Curves and equations are given for evaluating the quantities that are not ordinarily known by direct measurement. Some conventions are proposed for use in general radar range calculation, including an antenna-noise-temperature curve, minimum-detectable signal-to-noise ratio (``visibility factor´´) curves, and a formula for the reflection coefficient of a rough sea. A noise-temperature table and a work-sheet for range calculation are included in the Appendix.