Back in analog radar days (the 70's and earlier) Air Traffickers would announce the need to "put the Rain Plates in" when high levels of precipitation were such that clutter on both the azimuth and glide slope plots made it difficult to resolve an aircraft trace during a GCA.
My question concerns the technical nature of said Rain Plates. I assume they were some kind of primitive filter or attenuation technology ... but exactly what ... I can't recall. Anyone got a clue ?
In today's world a nifty bit of digital signal processing would easily be able to remove such noise ... both precipitation and ground clutter.
A bit of an anorak question I know
Best ...
Coff.