grid point at observation height $z_{\rm obs}=0.3$ Mm over typically $8{\leavevmode\kern.1em\raise.5ex\hbox{\the\scriptfont0 1}\kern-.1em/\kern-.15em\lower.25ex\hbox{\the\scriptfont0 2}}$ hours.

Filtering is applied in Fourier space, both frequency and wavevector. This is more efficient than repeating the simulation for a large number of monochromatic drivers. Wavevector filtering uses a circular Gaussian ball filter with standard variation $\sigma=0.1$ $\rm Mm^{-1}$ centred at a particular horizontal wavevector ${{\bmath{k}}}={{\bmath{k}}}_h$ oriented angle $\phi$ from the $x$-direction. Horizontal wavenumber $k_h=|{{\bmath{k}}}_h|=0.5$, 0.75, or 1.0 $\rm Mm^{-1}$ determines the skip distance and phase speed, and $\phi$ represents the wave propagation direction. Frequency filtering is centred on 3 mHz and 5 mHz with a 0.5 mHz standard deviation.

   $k_h$ ($\rm Mm^{-1}$)   $v_{ph}$ ($\rm km\,s^{-1}$)   Skip Dist (Mm)
  ----------------------- ----------------------------- ----------------
            1.0                       21.8                    14.7
           0.75                       29.3                    19.5
            0.5                       43.8                    38.8

  : Approximate phase speeds and skip distances associated with each of the three selected horizontal wavenumbers $k_h$ in the quiet solar model. \[tab:skip\]

The resultant filtered data cubes are analysed in two ways. First, the acoustic (slow) and magnetic (Alfvén) wave energy fluxes are calculated at $z_f=1.2$ Mm, just below the PML layer, and plotted as contoured functions of field inclination $\theta=0^\circ$, $10^\circ$, $20^\circ$, …, $90^\circ$ and wave orientation $\phi=0^\circ$, $5^\circ$, $10^\circ$, …, $180^\circ$ for 