Infra-sound surveillance system

US6570500B1 · kind B1 · utility

Assignee

• Nokia · FI

Inventor

• Norbert Pieper · Olfen, DE

Key dates

• Filing date: Nov 9, 2001
• Grant date: May 27, 2003
• Expiry date: Nov 9, 2021

Classification

• Technology area (CPC G): Physics
• CPC primary: G08B29/24
• WIPO field: Control
• WIPO sector: Instruments

Abstract

The invention is a method for monitoring an environment by evaluating an infrasonic signal obtained from said environment. The method includes averaging said infrasonic signal (Vinfra) to provide an averaged infrasonic signal (Vav), mapping said averaged infrasonic signal (Vav) according to a function to provide an infrasonic noise signal (Vnoise); averaging said infrasonic noise signal (Vnoise) to provide an averaged infrasonic noise signal (Vav noise); offsetting said averaged infrasonic noise signal (Vav noise) with an offset value to provide an infrasonic level signal (Vlimit); comparing said infrasonic level signal (Vlimit) with said averaged infrasonic signal (Vav); and generating a trigger signal (30) if said averaged infrasonic signal (Vav) is greater than said infrasonic level signal (Vlimit).