Residual cylindrically averaged power spectra after applying GPR. From left to right, top to bottom: direct FT inversion, nearest-neighbour gridding (no oversampling), default settings for WSCLEAN, default settings for IDG, increased oversampling and kernel size settings for WSCLEAN, and the same, but with a high number of w layers. To highlight the excess power, not all power spectra use the same colour maps. Black dashed line: Horizon wedge. Pink dashed line: Same with additional space for the windowing function. Blue dashed line: primary beam (5°) wedge. Gridding parameters are abbreviated as follows: o = oversampling factor, s = gridding kernel size, nwl = number of w-layers, and p = padding factor.