China builds mockups of U.S. Navy ships in the desert
I guess this means their DF21 uses some onboard optical system for terminal guidance, otherwise there would be no need for a physical mockup that visually resembles the intended target (it would otherwise be much easier to just designate a target region and measure afterwards if it landed in the region). Interestingly this might mean the DF21 is vulnerable to countermeasures that would interfere with the optics like a laser dazzler.