Demonstration of a spaceborne system to image seismic surface waves dynamically (i.e. coseismically) would be the early steps of a future operational capability for monitoring earthquakes and discriminating clandestine underground nuclear tests. Complementing the global network of seismic instruments, such system would enable unprecedented global mapping of the velocity structure of the Earth's crust, thereby improving hypocentral location, understanding of rupture dynamics and wave propagation effects, and source characterization. Seismic wave measurement requirements include lower bounds on detectability of events and wave amplitude accuracy for different levels of analysis, such as source characterization and crustal tomography, with 10-100 mum wave amplitude resolution for waves nominally traveling 5 km/s, an upper frequency bound based on earthquake surface displacement spectra, and minimum horizontal resolution (1-5 km) and areal coverage. Advanced radar technologies are keys to demonstrating a pre-operational system leading to a high MEO (10,400 km orbit altitude) constellation for continuous surveillance.

The development of a suborbital or spaceborne system to monitor seismic surface waves poses an intriguing prospect for advancing the state of seismology. This capability would enable an unprecedented global mapping of the velocity structure of the Earth's crust, event source location and characterization, and greatly improved understanding of earthquake rupture dynamics and wave propagation effects. Seismic wave measurement requirements include lower bounds on detectability of earthquakes and wave amplitude accuracy for different levels of analysis, such as source characterization and crustal tomography, with 10-100 mum wave amplitude resolution for waves nominally traveling 5 km/s, an upper frequency bound based on earthquake surface displacement spectra, and minimum horizontal resolution (1-5 km) and aerial coverage. The technological challenges to developing any such system are at this stage enormous. However, preliminary architectural concepts suggest feasibility in a far-term horizon while fostering collaboration on meeting scientific and operational challenges