“Visually, it is much too regular to not be man made.”
On the contrary, it is quite impossible for these features to be manmade. Humans dig canals by taking the top layers of soil off the ditch being dug and upturning those soils onto the bottom of the pile or dune alongside the ditch. As the digging of the canal progresses what was previously the top layers become piled atop the other top layers of soil and the former bottom layers are piled atop the pile or dunes to become the new top layers. In other words, humans digging a canal overturn the soil so the former top becomes the new bottom and the former bottom becomes the new top layer.
Natural linear dune formations do not dig up the strata and overturn them like humans do. The winds blow the sand into long and parallel dunes using sand and dust blown from the surface soils in the adjacent terrain. This sand and dust is progressively piled without a substantial movement of the dunes that would otherwise destroy the parallel symmetry created by the wind patterns. This results in an a long dune structure with the base atop the basement strata and progressing from the older dust and sand strata at the base of the dune to the newer strata of sand and dust at the top of the dune. In other words, the pile of soil is obviously not removed from the basement strata and is obviously not overturned. Instead the dune was piled into place with the old at the bottom and the new at the top, unlike manmade canals and dikes. Geological corings and studies of these formations have demonstrated quite conclusively these are natural linear dune formations running parallel, in part because there is no evidence of artificial or manmade overturnings of the soils in their formation.
Only God can make the wind blow straight enough over a large portion of this curved planet to explain this.
Time for more coffee.