TD maps of forward modelling results at z = 40 Mm. The upper and lower rows correspond to the LOS view and POS view (defined in Section 4), respectively. (a) TD maps of the Fe IX 17.1 nm line intensity with the original spatial resolution and a degraded resolution comparable to AIA. (b) and (c) TD maps of the Doppler velocity and line width with the original spatial resolution and a degraded resolution comparable to that of MUSE. Panels d–f: same but for the POS view. Panel d1: demonstrates how we obtained the wave parameters from the intensity TD maps. The tube centre positions are marked with black triangles, and the sinusoidal fitting results are depicted with a white curve.