Ptkay and Singaporecanac, peace will come only after someone makes public the name and number of radar equipment that ground control used. (It must be somewhere in the Polish 36th Air Force regiment papers from before)
(if we ever said it to the Poles, of course)
(Or may be Yak 44 pilots wandering around recognised it; radar is in the mid-length of the runway approx.)(they say in blogs)
What Smolesnk blog saw and took pics - by the looks of it, the chaps think it's smth No 6. The manual to this version 6 (found in the internet) has a part "Error by height". It seems quite awful, "error 100 m - when the plane is in settled steady glidepath landing" and "error 300 meters - to define a plane's position ? like, anywhere it is? off-hand? chancily?
When you simply want to see where is what, without previous ideas of it.
There was a discussion like, what the ground control then knows at all, ab the height, btw Far Beacon and Low Beacon (300 to 70 meters descend) and the answer was, type, of yrs of practice, seeing all the same on the screen every day, he ? somehow knows when a plane mis-behaves, things look odd, because all of them should move in the screen alike, the glidepath is one and the same, published in aerodrome manual and all.
Approx. so.
That's why I think un-healthy ground control interest in hearing the plane's heights told by the crew.