the round design looks like a test bed for ground zero events. Radiation, electrical interference, weapons, etc?
I don't know, therefore...
This seems simple. It's a regular runway and one for water planes :sneaky:
The grids of zigzagging white lines seen in two of the images the strangest of the various desert structures are spy satellite calibration targets. Satellite cameras focus on the grids, which measure approximately 0.65 miles wide by 1.15 miles long, and use them to orient themselves in space.