Hydrology Mission Requirements for a GRACE Follow-On

Matt Rodell
NASA Goddard Space Flight Center

Because satellite gravimetry is the only remote sensing technology able to measure water storage changes below the first few centimeters of the soil column, GRACE is already valuable for hydrological research, despite its low resolution relative to other measurements and other issues. Therefore, even a follow-on mission with identical performance parameters would be scientifically justified. Other factors like cost, technology readiness level, and accuracy limitations due to temporal aliasing are more likely to drive the requirements (though certain space agencies may be more likely to approve a mission that demonstrates a new technology). Nevertheless, it is useful to consider how theoretical improvements in resolution and accuracy would benefit hydrological research. This presentation will provide a preliminary assessment of the potential value to hydrology of such improvements.