Terrain Relative Navigation (TRN) Documentation

About TRN

• What is TRN?
  • TRN (Terrain Relative Navigation) is comprised of algorithms that enable autonomous platforms such as AUVs to use real-time bathymetry data to locate and navigate relative to a map. In this context, TRN is implemented as a software library (libtrnav), which may be used to develop TRN applications for different vehicles (platforms).
• How is TRN used?
  • Observing change is fundamental to understanding processes that affect the ocean. Being able to return to a specific place on the seafloor with high precision is not trivial. Even an inertial navigation system (INS) is subject to drift over the time scales used for mapping, for example, and typically requires acoustic updates from a ship to navigate with adequate precision.
    By navigating relative to a map, autonomous vehicles can, for example, quickly and independently find and follow previous survey lines, enabling researchers to make better comparative observations, while potentially freeing valuable ship resources.
    TRN has been used in MBARI's Ocean Imaging program to enable repeat mapping missions to help characterize geological processes and observe changes in areas of interest, e.g. an undersea volcano at Axial Seamount. TRN has been integrated with a variety of platforms, including MBARI's Dorado and Tethys AUVs, Woods Hole's Sentry AUV, and the MB-System open source mapping tools software.
• How was MBARI TRN developed?
  • TRN at MBARI was developed in a collaboration between Steve Rock's Aerospace Robotics Lab at Stanford and MBARI.

Acknowledgements

TRN Contributors

Stanford	MBARI
Stephen Rock Debbie Meduna Shandor Dektor Jose Padial David Stonestrom	Dave Caress Rich Henthorn Rob McEwen Kent Headley AUV Operations Group R/V Rachel Carson Crew ROV Ventana Pilots