Length Units for Visibility Analysis
Most properties of the visibility operators that are horizontal lengths (maxDistance, minDistance, sampleInterval) are given in meters. The exception is the firstResolutionChange, which is expressed in number of raster cells of elevation data near the observer, with the highest resolution available there.
The unit for the cell values in a raster feature is not specified by its feature CRS, so an elevation raster contains no information about its vertical unit. In the visibility operators, you can specify the VisibilityOperator.VerticalUnit that will be used for all vertical distances except for maxUpDistance, areaOfInterestBottomElevation and areaOfInterestTopElevation, which are always expressed in meters. Remember to express all vertical distances (apart from the three exceptions) in the same unit:
raster values from VisibilityOperator.ElevationInput,
raster values from VisibilityOperator.TreeHeightInput,
the z coordinate of an observer position whose LineOfSightOperator.CarrierType is Airborne,
the z coordinate of target positions (for TargetLineOfSightOperator),
the raster values in the color table of a viewshed (for LineOfSightOperator).
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