The rain gage coverage was designed specifically for use with the HEC-1 interface in WMS. The HEC-1 interface allows the xy coordinates of gages to be defined and then a series of Thiessen polygons created from the gages. When gages are present, weights are assigned to each basin from the Thiessen polygon network as the basin data are computed. Using the feature point create/select tools gages can be created/edited in a rain gage coverage by graphical selection as opposed to the HEC-1 interface where the coordinates are typed in explicitly. As feature points are created/edited a rain gage is simultaneously created (note that the feature point and the rain gage point are separate because it is still possible to create the gages without a rain gage coverage by typing in the coordinates in the HEC-1 interface). The only feature in the rain gage coverage is points.
Related Topics:
Feature Objects
Coverages