Secrecy News – Steven Aftergood: “This document… reviews the accessible literature for four research areas: source physics (understanding signal generation), signal propagation (accounting for changes through physical media), sensors (recording the signals), and signal analysis (processing the signal).”

Source: Trends in Nuclear Explosion Monitoring Research & Development — A Physics Perspective, Los Alamos National Laboratory, LA-UR-17-21274, June 2017.