[Type of Altitude issue] MAV_CMD_DO_SET_ROI_

ArduCopter
1

Hi all,

Here, on the official reference of the MAV_CMD_DO_SET_ROI_LOCATION message, we can see the description:
<param index="7" label="Altitude" units="m">Altitude of ROI location</param>

Could anyone please guide me which type of altitude is this?

  1. Altitude above ellipsoid
  2. Altitude above sea level
  3. Altitude above ground (=home position)