You have got me thinking Nico. Over the last few years I have been doing some feasibility studies of generating an in house orbit determination capability within AMSAT. Between the doppler measurements that you do and low cost interferometers that are now possible with cheap SDR dongles it seems like we can do OK here with a little work. I also understand that the SatNOGS people are doing work in this area https://gitlab.orekit.org/socis/satnogs-orbit-determination

My youngest is off to college later this year ... I will need something to keep me busy other than homework assistance and attending sporting events :-)

de KM1P Joe