Radargerät.

摘要

A marine radar has a screen (9) on which is displayed a radar image and several representations (22 to 26) of the different control functions of the radar such as range, gain and sea clutter setting. The radar also has a key pad (10) with three keys (13 to 15) and a tracker ball (12) that is connected to the radar control unit (1). The control unit (1) generates a marker (30) on the screen (9) that is movable by the tracker ball. To change one of the control functions, the tracker ball (12) is displaced until the marker (30) moves into the region of the representation of the appropriate control function. The control unit then produces three boxes (22A to 22C) on the screen below the control function (22) to indicate the different options available for that function. The user can select the desired option by pressing the appropriate one of the three keys (13 to 15).