The Delta h for any azimuth radial selected using the “Radial Truncation Delta h” slider will be displayed at the bottom of the slider and elevation box. Delta h calculations begin at 10 kilometers from the transmitting antenna and end at 50 km, unless you select a new end point. This can be done by clicking the “Delta h=" button and then inserting a new end point at the message prompt. Delta h radial elevation tables can be printed from the main screen "Print" --> "Print delta h table" menu.
The terrain elevation sampling interval can be changed by selecting the "Defaults" menu item and then selecting "Set Terrain Spacings."