초록 ▼

A motion alarm system having a combination of microwave and ultrasonic subsystems is operative to reliably detect true moving targets and to discriminate false targets both caused by target motion reflected outside the surveillance space and by noise and other interfering phenomena. Microwave and ul

A motion alarm system having a combination of microwave and ultrasonic subsystems is operative to reliably detect true moving targets and to discriminate false targets both caused by target motion reflected outside the surveillance space and by noise and other interfering phenomena. Microwave and ultrasonic signals received from the surveillance space are separately processed to provide ultrasonic motion detection signals and a microwave motion detection signal. A signal processing circuit interdependently combines the signals for producing a correlated system event signal. The presence of a true moving target within the surveillance space produces sufficient correlation to cause the system event signal to meet predetermined alarm criteria. The presence of either interfering phenomena or unwanted reflected outside signals, or both simultaneously, produces insufficient correlation to cause the system output signal to meet the predetermined criteria. An alarm status is thereby only provided in response to a true moving target within the surveillance space, but not in response to the occurrence of error producing sources for the sub-systems individually or collectively.

대표청구항 ▼

An intrusion detector system, comprising: first means for providing first and second motion detection signals in response to ultrasonic energy received from a protected volume that are respectively representative of motion in opposite directions; second means for providing a third motion detection s

An intrusion detector system, comprising: first means for providing first and second motion detection signals in response to ultrasonic energy received from a protected volume that are respectively representative of motion in opposite directions; second means for providing a third motion detection signal in response to microwave energy received from the protected volume; and third means coupled to said first means and to said second means and operative in response to said first, to said second, and to said third motion detection signals for providing an alarm signal indication of intruder motion in the protected volume when at least one of said first and said second signals are simultaneously present with said third signal and when one of only one of said first and said second signals is correlated with said third signal.