359 / | HD | OPTICS: SYSTEMS (INCLUDING COMMUNICATION) AND ELEMENTS |
838 | DF | MIRROR {14} |
850 | DF | .~ Plural mirrors or reflecting surfaces {7} |
851 | DF | .~.~ Composite or echelon mirrors or light concentrating array {2} |
853 | .~.~.~ Light concentrating (e.g., heliostat, etc.), concave, or paraboloidal structure |