This type of system relies on constellations of satellites as transmitters of opportunity, with the receiving segment being on the ground.
Constellations of navigation satellites, i.e. GPS, GLONASS and Galileo were used simultaneously as the proving platform for this purpose. Two technology demonstrators were built for this purpose, one of which as part of a European H2020 consortium (project SpyGLASS). The demonstrators were capable of synchronising a multitude of different satellites as part of a coherent network, and illustrated the benefits of multi-static space-based radar for marine targets. These were verified through long-term experimental campaigns in Portsmouth (UK), the river Rhine (Germany) and the port of Venice (Italy).
Multi-static radar target phenomenology as well as novel approaches for marine detection and location using up to 12 satellites simultaneously were developed and successfully tested as part of these campaigns.
We are currently working with colleagues at DSTL to establish the feasibility and performance of broadband internet satellite illuminators of opportunity, such as Starlink and OneWeb.