1. Create grid frame. With the STWAVE coverage active, do the following: Use the Create 2D Grid Frame tool to define a the grid frame. Using the Select 2D Grid Frame tool, double-click on the grid frame. In the Grid Frame Properties dialog, edit the grid frame properties and assign elevation data. 2. Convert coverage to 2D Grid. Right-click on the STWAVE coverage and select the Convert | Map → 2D Grid command. In the Grid Frame Properties dialog, review the grid frame properties and assigned elevation data.