The inaudible symphony: on the detection and source identification of atmospheric infrasound

摘要: Sound becomes inaudible if it consists of frequencies lower than 20 Hz, i.e. the human hearing threshold, and is called infrasound. Low frequency acoustic signals were first discovered after eruption Krakatoa (Indonesia) in 1883. Due to its low content, this infrasound traveled up seven times around globe while reaching altitudes over 100 kilometer. The ability detect explosions with resulted substantial scientific societal interest during World War I era atmospheric nuclear testing. This diminished as tests confined underground under Limited Test Ban Treaty 1963. Recently, signature Comprehensive Nuclear-Test-Ban Treaty, gained renewed attention being used a verification technique. thesis describes complete sequence measuring, processing interpreting data. A microbarometer was developed deployed arrays measure Array statistical detection techniques are applied extract from continuous recordings. Knowledge on propagation appeared essential identifying infrasonic sources, like meteors, volcanoes, sea waves accidental chemical explosions. large amount coherent continuously detected both natural man-made symphony. Applications foreseen remote sensing where can be passive probe for upper atmosphere. Non-acoustic phenomena, gravity waves, also methods described thesis.