The Seekable TN-1
The TN-1 is a passive-source electromagnetic (pEM) cable tracking system developed by Seekable to meet the operational and technical demands of today’s offshore power cable projects. It is engineered to operate in a wide range of environments including intertidal zones, shallow waters, and offshore deepwater conditions. The TN-1 introduces several key innovations that distinguish it from the current generation of cable tracking systems:
Model-Based Tracking: The core of the TN-1 system is a model-based approach that matches live sensor readings with a modelled magnetic field informed by a cable verification test on shore. This approach allows the system to produce more accurate position estimates than conventional raw signal-following methods.
Off-Axis Detection: The TN-1 is capable of tracking cables even when the sensor array is not directly above the cable up to 10-12 meters total distance. This is critical for operations in uneven terrain, fast currents, or where precise centering of the ROV or towfish is impractical.
Multi-Environment Adaptability: From beach landfalls to offshore trenches, the TN-1 is designed to adapt quickly to the specific needs of each project without requiring hardware reconfiguration. The TN-1 can be mounted on towed frames for marine surveys or on drones for intertidal or onshore surveys.
In its current form, TN-1 detects only energized (live or actively toned) cables. However, Seekable is actively developing an acoustic module to extend tracking capability to unpowered cables in future releases.
Product properties
Click here to download the spec sheet PDF
Survey speed: up to 4 knots when mounted on towed wings.
Sensors: Sensys 3-axis fluxgate magnetic sensors made in Europe.
Depth Rating & Durability: The standard TN-1 system is rated for operations up to 300 meters water depth. For deeper surveys, a specialized digitizer and sensor configuration is available, supporting deployments down to 3000 meters.
ROV, Towfish & UAV Integration: The TN-1 is typically deployed by rigid mounting in front of or behind an ROV, or towed behind a survey wing such as the EIVA ROTV (e.g., ScanFish). High-accuracy nonmagnetic heading as well as pitch and roll are required, which can be supplied by the carrying vehicle or provided by Seekable.
Additional properties
Data storage: in a HDF5 file.
Scaling factor: can be compensated for.
Post-processing: on multiple frequencies.
Multiple inversion models to choose from.
Data transmission via network interface
Simultaneously record magnetic data for UXO surveys.
Not disruptive to marine life.
