where we assumed all contributions to our measurement uncertainty statistically independent and thus got sum uncertainty by summation of standard deviations. If we further assume that all light pulses are similar and have the same phase uncertainty, thence Δ Δ x m e a s ( t j + 1 ) = Δ Δ x m e a s ( t j ) ≡ ≡ Δ Δ x m e a s = Δ Δ ϕ ϕ / ( 2 k p ) .