Edge sensing apparatus and method reducing sheet fly height error

An edge sensing apparatus is disclosed including first and second emitters, first and second detectors and a timer. Beams radiated from the first emitter being emitted in an opposite direction from beams radiated from the second emitter. The first and second detectors being aligned to receive beams from the first and second emitters respectively, where the first detector is offset in a cross-process direction from the first emitter and/or the second detector. The timer receiving signals from both the first and second detectors, wherein a change of the signals determines a position of an edge of a substrate media sheet causing the change of signals. Also, an edge sensing method is disclosed including measuring a mean time associated with a change of signals received from the two detectors and determining a location of a sheet edge causing the change of signals based on the mean time.