The A-scope display, shown in the figure,
presents only the range to the target and the relative strength of the echo.
Such a display is normally used in weapons control radar systems. The
bearing and elevation angles are presented as dial or digital readouts that
correspond to the actual physical position of the antenna. The A-scope
normally uses an electrostatic-deflection crt. The sweep is produced by
applying a sawtooth voltage to the horizontal deflection plates. The
electrical length (time duration) of the sawtooth voltage determines the
total amount of range displayed on the crt face.
The A- scope display is using in older radar
sets only as monitoring oscilloscope. In modern digital radar sets don't
exist a similar targets videosignal. The target messages are transmitted to
the displays as a digital word. There isn't any possibility to get a
synchronizing signal for these asynchronuous serial digital signals. Well,
the oscilloscope can get an internal trigger only. Therefore it is
impossible to analyze the bit sequence with a simple oscilloscope. The only
one statement is possible: a digital word is existent, that means, obviously
the drivermodul for this line works.
A control-pulse shown at an A-scope of the russian VHF-radar �Spoon
Rest�
