Video camera-based vibration measurement for Condition Assessment of Civil Infrastructure

Recent work has used cameras and computer vision techniques to qualitative and quantitatively analyze the motion of objects. This paper presents a method to measure vibrations with a video camera for condition assessment of civil infrastructure. As a proof of concept, a camera was used to measure an antenna tower, also known as a crow’s nest, located atop the Green Building on the campus of the Massachusetts Institute ofTechnology. The measurement was made from a distance of over 175 m and correctly identified the resonant frequency of the crow’s nest, confirmed by a close-proximity laser vibrometer measurement. By tracking changes in the resonant frequency and other properties of the ambient vibration signal a general sense of the structure’s condition could be determined as a basis for more in depth non-destructive testing.