Radar Basics

Range/Height Indicator (RHI-Scope)

The Range-Height Indicator (RHI- scope) is used with height-finders to obtain height information. The RHI is a two-dimensional presentation indicating target range and height. The sweep originates in the lower left side of the scope It moves across the scope, to the right, at an angle that is the same as the angle of transmission of the height-finding radar. The line of sight to the horizon is indicated by the bottom horizontal line. The area directly overhead is straight up the left side of the scope. Target echoes are displayed on the scope as vertical blips (spots of increased intensity that indicate a target location). The operator determines height by adjusting a movable height line to the point where it bisects the center of the blip. Target height is then read directly from an height dial or digital readout. Vertical range markers are also provided to estimate target range.