Your sentence doesn't even make sense. Think about a mother calling up to her son: "Are you up?"Where is he? Upstairs (oben) in his bedroom.
can it be used like "über"? that something is above my head? Es ist oben mir?
No, the two are completely separate: oben is an adverb (just “above, upstairs” on its own) while über is a preposition (“above something”). Neither can be substituted for the other.
Old High German obana, adverbial form of obar (over) < Proto-Germanic *uber. It’s cognate to the “-ove” part of English “above” < Old English ”ābufan” < “a” (at) + “bufan” (over) (and “bufan” itself is originally “be” (near?) + “ufan” (over)).
Wow; you really deserve more than one lingot for that explanation. you must be a teacher. ^___^