RAD is the functional limited edition of the advanced acoustic research Système DSSF3. The point that RAD differs from other systems completely is that a time change of sound can be analyzed in detail at a high temporal resolution. Using RAD, various sound qualities such as loudness, total quality, pitch and the movement of source can be analyzed by the running ACF measurement. Broad examples of measurement are considered, such as a measurement in a concert hall, measurement of a home audio and car audio, tuning of a musical instrument, aircraft noise measurement, traffic noise measurement, analysis of toilet noise, musical instrument music analysis, voice analysis, performance measurement of a motor, measurement of the operation sound of an air-conditioner, and heartbeat measurement.