altitude hole

altitude hole

[′al·tə‚tüd ‚hōl]

(electronics)

The blank area in the center of a plan position indicator-type radarscope display caused by the time interval between transmission of a pulse and the receipt of the first ground return.

altitude hole

The blank area at the origin or center of a radial display, on a radar tube presentation, the center of the periphery of which represents the point on the ground immediately below the aircraft. In side-looking airborne radar, this is known as the altitude slot.