def METHOD_NAME(aa_crepr, observed_frame):
    # remove refraction from AltAz cartesian representation
    refa, refb = erfa.refco(
        observed_frame.pressure.to_value(u.hPa),
        observed_frame.temperature.to_value(u.deg_C),
        observed_frame.relative_humidity.value,
        observed_frame.obswl.to_value(u.micron),
    )
    # reference: erfa.atoiq()
    norm, uv = erfa.pn(aa_crepr.get_xyz(xyz_axis=-1).to_value())
    # Cosine and sine of altitude, with precautions.
    sel = np.maximum(uv[..., 2], SELMIN)
    cel = np.sqrt(uv[..., 0] ** 2 + uv[..., 1] ** 2)
    # A*tan(z)+B*tan^3(z) model
    tan_z = cel / sel
    delta_el = (refa + refb * tan_z**2) * tan_z
    # Apply the change, giving observed vector.
    az, el = erfa.c2s(uv)
    el -= delta_el
    uv = erfa.s2c(az, el)
    uv = erfa.sxp(norm, uv)
    return CartesianRepresentation(uv, xyz_axis=-1, unit=aa_crepr.x.unit, copy=False)