🚀 go-pugleaf

The top of the line RADAR screens available today (such as FURUNO's, for
example) have a display which is a CRT, just like your computer screen, so
the whole screen, including all contacts and the scanning line, are
redrawn multiple times every second, since they are represented as pixels,
not simply as persistent phosphor glows......

They have all sorts of options, so the range rings, overall range
displayed, brightness, and display of the scanning line are all determined
by the user...  if you opt not to display the scanning line, it is still
possible to see where the antenna is by watching the objects represented
on the screen change with each pass of the antenna... One neat trick is
that they have a cursor controlled by a tracball which can tell you the
distance from you to any contact on the screen.

Most of the other skippers to whom I've talked prefer to display the scanning
line.  One reason for this is that it's possible to freeze (intentionally
or not) an image on the screen (since it's a pixel image) and the rotating
scanning line confirms that the display being seen is an active one.
-- 
Jim Welch
University of Delaware
Graduate College of Marine Studies
jimwelch@ravel.udel.edu