A network of global monitoring of positions of geostationary satellites by their payload radio signals

Continuous high-precision non-invasive tracking of active geostationary satellites is an urgent need. The solution to this problem may be the creation of simple VLBI networks.The main method of functioning of such networks is the passive correlation ranging (PaCoRa). The ESA project PaCoRa was executed by Fraunhofer Institute for Integrated Circuits (IIC) and SES during the years 2010-2013. The simple VLBI network consisting of 5 stations has been in operation in Ukraine and Latvia since 2015. The Chinese network consisting of 4 stations started observations in June 2019. The networks have identical hardware and software. The synchronizing error is 20 ns, which causes the accuracy of satellite coordinates determination at a level of 200 m. The simple VLBI network proposed for the global monitoring of active geostationary satellites may consist of clusters. The list of works on upgrading existing networks is presented to reduce the measurement error and ensure complete automation of the network's operation.