Monitoring the tests: Missile flights and test explosions are watched closely to determine whether an adversary´s new weapons might upset the strategic balance

US monitoring capabilities related to the surveillance of Soviet strategic forces are reviewed and assessed. Data collected during the testing of military systems and the information derived from it are discussed. The author describes various information gathering systems (satellites, radars, ground sensors, sea sensors) used in the detection of missile telemetry signals, and of land-based military systems. Emphasis is on the detection of Soviet nuclear weapon and missile testing along with their implications for strategic arms limitation treat constraint verification.