cfr I am surprised by your comments. Maybe you need to try a higher hover height if the aircraft is moving around a lot. Not sure what parameters you have set for the Autohover. We do ours at 75-100' with not many dramas but sea state usually a bit lower.
Curious2, We used to set Radalt height at 70-80 feet for low deck vessel operations.
As sea state increases, we increase hover height safety margin as well. For a 4-meter swell, hover alt is about 100' (depends on on-scene conditions)
Over 4/5-meter swell Radalt oscillation is excessive (up to +-20')
Even worse, vertical movements are completely "desynchronized" with swell.
When the wave goes up, helicopter goes down...
That means system makes collective inputs larger and larger.
At one point it is unacceptable and we back to Manual mode (even at night)
Over 6-meter swell is more difficult to "fight" against autohover system than revert to Manual mode.
VelHold is not good too...
More than 30Kts headwind and we need to beep forward up to 3-4 Kts to maintain position.
Real "0 longitudinal /0 lateral doppler" (pressing chinese hat) only works with light and moderate winds (less than 25-30 Kts).
Sea State HIGH is selected on Doppler menu.
What about Doppler wave? When do you select CW/CCW?