Mark Dickson wrote:
Unless the glider was transponder equipped, the only
radar that could give the height would be a Precision
Approach Radar (Talkdown). This only scans 10 degrees
either side of the runway centreline and is not widely
used at civilian airports. If ATC knew the height
I think it would have been via a report from another
aircraft.

Back in "good old days" I worked on a CPS 6B which gave
height by a second "slant" beam displaced from the
"vert" beam by, as I remember 10 deg.
Gosh that was a LOOOOONG time ago. :-)
...lew...