The three Dimensional maps created a revolution in the field of navigation and medical and also in the engineering field. The advantage of 3D maps are that it can give the idea of all the dimensions and hence better designs can be created by looking at the 3d maps and the conventional maps were not that much informative compared to 3D maps are

It is the direction the radar is facing. It allows the radar to determine where the object is located in 2D or 3D space.

It provides a 3 dimensional image. Older radar shows a 2 dimensional image.

Both.

Original radar is 2D and was invented in 2D.

Modern radar is in 3D and is generally used for ground penetrating radars. Eventually 3D will be incorporated into new modern warships and air defences.

A three band radar detector can read signals from 3 different band widths. This comes in handy with the new types of police equiptment out there.