A discrete Fourier transform on a q-linear grid is presented. Several
of its analytic properties are discussed and compared with the
continuum situation. We recognize that a special invariant of the
related Fourier operator is closely connected to discretizations of
the Hermite functions. This result is similar to the continuum
scenario and reveals a key role of the q-Fourier transform to the
understanding of difference equations. The continuum limit q1 in the
sense of strong L2-convergence is investigated for the derived
q-Fourier invariant generalization of the Gauss curve. Applications to
Schrödinger difference equations are briefly mentioned.