Description: | In this colloquium, I will talk about the effects of interference on radio astronomy caused by human devices. Human devices can interfere with radio-astronomical observations. Therefore, telescopes are often build in remote areas with a very low population density. However, building telescopes at remote locations is costly. LOFAR has taken a different approach by building antenna fields all over populated areas of the Netherlands. This has raised concerns about the harmful effects that human devices could cause.
This colloquium addresses these concerns. We have designed several automated methods that can excise interference from radio observations. I will show that these techniques remove the interference from the data with an unprecedented accuracy. We extensively analyse the resulting data and conclude that after the application of these filters, we can make very sensitive maps of the sky with LOFAR. Consequently, it appears it was an excellent decision to build LOFAR in the Netherlands. Furthermore, we analyse the properties of interference using source count analysis, similar to analyses used in cosmology, and find a few surprising conclusions. |