Here we outline some new technologies in this context within case studies from different research projects including permanent installation of fiber-optic sensor cables behind casing, monitoring of high-temperature wells, a hybrid wireline logging system, and seismic. Here we outline some new technologies in this context within case studies from different research projects including permanent installation of fiber-optic sensor cables behind casing, monitoring of high-temperature wells, a hybrid wireline logging system, and seismic. New methods in geophysical exploration and monitoring with DTS and DAS New methods in geophysical exploration and monitoring with DTS and DAS J. Reinsch 1 1 GFZ German Research Centre for Geosciences 2 BAW Federal Waterways Engineering and. Conventional measurement systems: usually based on electronic sensors. Limitations: temperature, complexity, cost. Raman: inelastic scattering, interaction with molecular vibration and rotation. High-temperature measurements above 1000 °C are critical in harsh environments such as aerospace, metallurgy, fossil fuel, and power production. Fiber-optic high-temperature sensors are gradually replacing traditional electronic sensors due to their small size, resistance to electromagnetic. Permanent downhole fiber-optic cables are critical infrastructure in wellbore monitoring systems, ensuring reliable transmission of data for applications such as distributed temperature, acoustic, and strain sensing (DTS, DAS, and DSS)—all with one 1/4-in control line. These monitoring systems help. VIAVI OTDRs allow technicians all over the world to characterize optical cables by measuring the optical length, the global loss and, the common events such as splices, connectors and slopes that affect cable performance and signal transmission.