DTSS technology is based on Brillouin optical scattering, which responds to both, temperature and strain along the optical fiber. When a laser pulse is launched into the fiber, light is scattered back due to the interaction with the fiber material. The optical properties of the backscatter, such as frequency and amplitude, vary depending on the temperature and strain applied to the fiber. This data is continuously analyzed. The system uses optical time domain reflectometry (OTDR) to precisely locate where changes are happening by measuring the time delay of the returning signal, much like radar.