(For anyone who doesn't recognise this from the title - this is a talk by one of the designers of the Keyhole 9 spy satellite.) 22-23 minutes in he talks about

(For anyone who doesn't recognise this from the title - this is a talk by one of the designers of the Keyhole 9 spy satellite.) 22-23 minutes in he talks about resolution of the KH9 spy satellite photos, and says (to paraphrase) "The declassified resolution is 2-3ft... The resolution is much better - I can't tell you what though" Anyone have a better estimate of resolution - and how this might compare to the current generation up at the moment?