Often, simple curiosity is enough to do something. This is also the case with people trying to analyze the configuration and communication protocol SpaceX uses with their Ku-band-based Starlink satellites. One of those good people is [Christian Hahn], who recently published some early findings on r / StarlinkEngineering on Reddit. Some of the data captured appears to include the satellite identification system that user ground stations would presumably use to track Starlink satellites in the air.
For the capture itself, [Christian] uses a second-hand dish for capture and a DIY SDR using hardware based on the KC705 FPGA – which may have started life as crypto mining hardware – along with the usual assortment of filters and other components common with this type of capture. Even at this early stage, some features of the Starlink protocol seem fairly obvious, such as channeling and using on-call periods. Nothing too overwhelming, but as a fun SDR hobby, it definitely checks all the boxes.[Christian] also announced that at some point he would create a website and publish the results and code that should make Starlink signal analysis easier for anyone with a readily available SDR receiver.