Determination of the scale height of the λ862 carrier by the DIB measurements with 4° ⩽|b|⩽12°, and upper panel: 240° ⩽ℓ⩽330°; lower panel: toward all available longitude directions, respectively. The data points at different latitude slabs are coloured according to the central latitude values (b₀). The dashed green line indicates z = 0.4 kpc. The red curve in the upper panel is the fit to data points with z ⩽ 0.4 kpc, while in the lower panel, the red curve is the fit to all the data points.