The patent relates to a line spectrum detector to distinguish motor vehicles acoustically in the presence of background noise. The detector senses periodic signals, such as the firing rates of internal combustion engines, by using a swept phase-lock loop spectrum analyzer and passes the sensed signals to a logic network which measures the frequency stability of the sensed signal to distinguish motor vehicles from aircraft vehicles and the like.
Vehicle Detector
1970
7 pages
Report
Keine Angabe
Englisch