Minimum Detectable Radar Signal and Its Dependence upon Parameters of Radar Systems

This paper presents results of an early study of the influence of parameters of a pulse radar system on its sensitivity. More specifically, it describes an experimental determination of the absolute value of minimum pulse signal visually detectable through random noise with a probability of 50 per cent for a wide range of the following parameters: pulse-repetition rate r, pulse length t, intermediate-frequency bandwidth B, and video bandwidth b. The following empirical formula expresses the results of the investigation with considerable accuracy: 1/ 1 \/ 1670\ 1/ 6 Vmin =-E. B112I1 +-1 ) 2 \ tB/ r/ where V
min
is the minimum detectable pulse voltage and E
n
is the noise voltage per unit intermediate-frequency bandwidth of the receiver. The application of the results to the design of search radar systems is briefly discussed.