and finally into an AirSpy SDR. GNURadio was used to build the spectrometer needed to determine the galactic rotation curve, or the speed of rotation of the Milky Way galaxy relative to distance ...

[Kaushlesh] used an Airspy HF+ Discovery, a compact receiver that can work the HF and VHF bands, but it’s easy to modify the SDR Dock to accept other types like those ubiquitous RTL dongles.