Question about how to make minimum separation
I heard that in busy airports, controllers wish to make two aircraft approaching on same runway with minimum separation when preceding aircraft touchdown.
But I still could not find the right way to make sure two aircraft will not less than the minimum, because that is too close to minimum, for example, 3miles is minimum, but 2.9 is an incident. I know to tell pilots maintain certain speed to certain position, I always tell pilots to maintain 180Kts to 7 miles touchdown, but after 7 miles some pilots reduce speed slowly, some reduce speed to minimum very very fast, that is unable for me to predict.
Can somebody give me some advice about it?
Appreciate