Uncertainty weighting uses an IHO S-44 survey order to determine the area of influence that a sounding can apply to the nodes.
A sounding’s area of influence (the number of nodes to which a sounding is applied) is determined by the vertical uncertainty limit in the selected S-44 survey order. When a sounding’s vertical uncertainty increases beyond the requirement for the survey order then it cannot contribute to the node.
The a (constant depth error) and b (factor of depth dependent errors) fields are automatically filled when a survey order is selected. The values are read from C:\Program Files\CARIS\HIPS\<version>\System\IHO_Standards.xml.
The values in the “a” field show the constant depth error value associated with the selected S-44 survey order.
The values in the “b” field show the factor of the depth dependent errors value associated with the selected S-44 survey order.