Measuring low‐frequency noise indoors

Measuring owl flight noise

It is well known that most genera of owls are able to fly almost silently in order to hunt their prey. However, this knowledge is actually based on very few quantitative studies only. This is especially interesting regarding the fact that, against the background of increasing air traffic, the unique plumage adaptations of the owl responsible for the silent flight are the motivation behind vario...

Measuring Sound and Noise

The European Community Green Paper on Future Noise Policy (1996) recognised that environmental noise is “one of the main local environmental problems in Europe” but that it has had a lower priority than other environmental problems, such as air or water pollution. It also recognised that, despite significant reductions in the noise produced by individual sources, total exposure to environmental...

Measuring trapped noise in metamaterials

Robust Heading Estimation Indoors

The problem of estimating heading is central in the indoor positioning problem based on measurements from inertial measurement and magnetic units. Integrating rate of turn angular rate gives the heading with unknown initial condition and a linear drift over time, while the magnetometer gives absolute heading, but where long segments of data are useless in practice because of magnetic disturbanc...

Alternative Theories of Atmospheric Teleconnections and LowFrequency Fluctuations

Observational studies have revealed a rich low-frequency structure in the atmosphere. A review of the theories, observations, and model studies of this low-frequency atmospheric variability is presented. On time scales of weeks or longer the atmosphere appears to possess distinct oscillatory behavior in welldefined and persistent "centers of action." This behavior is also an endemic feature of ...