Here’s an instance from the Dictionary of English Surnames (1991):
Same dudes show up in The Oxford Dictionary of Family Names in Britain and Ireland. So in that case, at least, the name is not related to the placename “Chiltern” but rather to “Children” as in “orphanage”. The “atte/ate” is clearly a form of “at”, though.
Hey Yllaria, remember this? 
Ah, iron shrubbery. Brings back the bucolic yesteryear. Et in Arcadia tu.
Actually, “so and so of the Green Gables” I’ve heard and still don’t understand, but at least I know what iron shrubbery is, or could be.
West is a fairly common surname and means different things but one example is it was bestowed on some French soldiers who remained in England after the Battle of Hastings 1066. Well that is according to our family lore.
I suspected that I’d mentioned “ate Children” before, but forgot the rest of that post. I could live with the surname Hyperion.
Looks like the old link has succumbed to bit rot. So: Hyperion.