Side-Tracking Capability Design Use-Cases

There are two popular design scenarios for side-tracking capability, position hold and dead reckoning.

Position hold is designed to be used to hold the ROV in place next to a feature in the presence of disturbances such as current flow and tether drag. The typical side-tracking usage would be to point the DVL at the target surface, as close to perpendicular as you can make it. The DVL will lock on and begin outputting position and orientation deltas.

When dead-reckoning in side-tracking mode you will normally be using the world-frame mode. See the discussion in the background section above on how dead-reckoning coordinate accuracy might be affected.

Note: the dead reckoning in world coordinate space may be distorted by the magnetic field of the target surface, which will typically look like warping the latitude/longitude grid diagonally.

Note: You may be able to integrate the ROV X-Y-Z velocities when in side-tacking mode to measure distance moved with respect to the target surface. Accuracy would be affected by several factors including magnetic influences and target surface reflectivity characteristics.