Real time tidal currents

General Discussion
5

Right, so if I’m understanding you correctly, the potential value adds would be

  1. more responsive control, because the navigation filter knows about some potentially significant external forces
  2. given a reasonably accurate position estimate and tidal currents map, could act as an early warning system to a pilot of strong currents their vehicle may not be able to handle
  3. possibly more effective inertial navigation, because the vehicle’s inertial measurements could be used together with known tidal currents and control inputs, and a model of the vehicle’s dynamics and thrust capacity, to try to simulate the vehicle’s motion

Those would come at the cost of needing to take some tidal water speed measurements (where it’s relevant to ask: how many? over what time period? how expensive are the sensors to have, deploy, and use?), and possibly some significant computation for the last point.

Is that about right, or are there other values or costs that I’m missing? :slight_smile:

I’m intrigued by this, as it would seem to require one or multiple current sensors on the vehicle, which I understand isn’t particularly standard in the ROV world. I did a quick search and found a somewhat brief discussion about the idea here, but that was seemingly dismissed on the assumption that the currents around the vehicle aren’t known (in which case it’s understandably not a particularly useful sensor to have unless the aim is to measure currents given known vehicle velocity+position).

I’d be interested in how significant these are in practice. While they may average out to be insignificant given enough time, I imagine the majority of vehicle navigation doesn’t occur over such broad time frames. I also understand that the effects of wind and air pressure are most pronounced at shallow depths, since they apply at the water’s surface.

Do you have a particular use-case in mind where you think tidal currents solves a currently unmet need, or is your experience more with the detection and estimation side and you’re hoping to find such a need through this discussion? :slight_smile: