Oral Abstract

Oral Contribution (O7.4) Benjamin Winkel (Max-Planck-Institut für Radioastronomie (MPIfR))

Theme: Telescope operations and scheduling: from classical to autonomous

Starlink, OneWeb and 5G - A new dark age for radio astronomy?

In 2019 SpaceX launched the first of 12000 Starlink satellites, which aim to provide global broadband Internet access. Astronomers have to fear a massive increase of satellite streaks in optical images. But also at radio wavelengths, we will suffer immensely. In the Digital Revolution, mega-corps have insatiable hunger for bandwidth to power applications such as virtual reality applications or >4K streaming even on people's mobiles. Huge parts of the spectrum need to be allocated to these services. As a consequence radio telescopes are blinded in these bands!

Nevertheless, we should not give up. Radio frequencies are subject to international rules and thus we can fight for a fair share of the spectrum. Compatibility studies form the basis of these activities, in which the potential impact of new services on observations is analysed. If one can demonstrate that harmful interference would be caused, administrations have to act - either by enforcing transmitter-side mitigation techniques, or by not granting licenses at all.

A Python package, pycraf, was developed for performing compatibility studies, offering modules to calculate propagation losses in real terrain, atmospheric attenuation, or satellite positions, and much more. Pycraf is open-source, hosted on GitHub (https://github.com/bwinkel/pycraf) and distributed via PyPI and conda-forge. It has extensive documentation and comes with many examples. Some of the functionality, especially the propagation loss calculations, are computationally demanding. I will explain how a combination of clever algorithms and parallel processing, powered by Cython, make pycraf at least an order of magnitude faster than other existing software tools.