Radar System Performance Charts

The fundamental limits to radar performance in search and tracking can be expressed on three charts, in terms of products involving transmitted power, antenna gain, and effective aperture area. Locations of past and present radar systems on these charts disclose evolutionary trends in system design and indicate regions of practical and economic balance between transmitter and antenna complexity, in terms of ratios of power to gain and aperture. The basis of choice for operating frequency is clarified for different applications of radar, such as air surveillance, precision tracking, weapon control, and combinations of these tasks. It is suggested that these historical trends, derived from a large sample of successful radar systems, will furnish a better guide to economic optimization than will empirical cost equations. They are also helpful in comparing diverse approaches to radar system design, and in estimating the dependence of proposed systems upon new component and technique developments. The examples used in this paper are drawn primarily from ground-based radar systems, and serve to clarify the relationships between conventional and phased-array radar systems used for aircraft and missile detection, tracking, and weapon control.