Short-spacings correction for the JVLA absorption data. As an example, sight line 1 of the DR 21 source is shown. The black line is the original HI4PI spectrum, the red line is the JVLA data smoothed to HI4PI resolution, and the green line is the resulting short-spacings contribution. For comparison the result of the ring-filter operation, applied to the Galactic plane survey data cube, is displayed in blue (with 1σ uncertainties).