To use RTK tides using a RTK receiver and a geoid model, it is required to set the height of the antenna above the water surface. Please note that you use the phase center of the internal antenna instead of the bottom of the antenna.
If you do not configure a draft for the echosounder, it is also possible to set the offset between the antenna and the bottom of the transducer. Please note, that in this case the RTK tide level displayed is the level at the bottom of the transducer !
We suggest to set the antenna height as height above the water surface, and use a draft value for the offset between the transducer and the water surface. This way, the tide level recorded is always the level of the water surface.
When antenna and transducer are mounted on the same pole, the distance between the antenna phase center and the bottom of the transducer should be equal to draft + antenna height.
When using RTK, the tide level is calculated as follows:
_Tide = Ellipsoid Height - Separation by geoid model - Antenna Height._
