NNSA builds the nation’s operational sensors that monitor the entire planet from space to detect and report surface, atmospheric, or space nuclear detonations; produces and updates the regional geophysical datasets enabling operation of the nation’s ground-based seismic monitoring networks to detect and report underground detonations; and conducts research and development on nuclear detonation forensics, improvements in satellite operational systems to meet future requirements and size/weight constraints, and radionuclide sampling techniques for detection of worldwide nuclear detonations.