Duga was a Soviet over-the-horizon radar system used as part of the Soviet missile defense early-warning radar network. The system operated from July 1976 to December 1989. Two operational Duga radars were deployed, one near Chernobyl and Chernihiv in the Ukrainian SSR (present-day Ukraine), the other in eastern Siberia.

The artwork on this patch is taken from a part of the mural in one of the administration buildings of the Duga radar system in Chernobyl - seen here.

The original photo was taken by Winslow Dumaine - website.

Specs:
14cm x 8cm (this thing is pretty big)
Embroidery, merrow border