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Well, partly, but that was because the stereotype already existed. The horned helmet appears in some 18th-century illustrations, and in a great many early 19th-century books about the Vikings, well before the Ring came on the scene. Winged helmets appeared in the 19th century, equally spurious. As many people point out, no such horned or winged helmet has ever been found, and they would have been dangerously impractical in a fight, so they're generally dismissed as a romantic myth. But in fact there was some justification for it, from very early discoveries. The famous golden horns of Gallehus in Denmark, discovered in the 17th and 18th centuries (and promptly melted down by a counterfeiter) are recorded as embossed with dancing warrior figures, and some of these wear high-horned helmets. So does a presiding god-figure on the Gundestrup cauldron, and similar figures on the helmet-plates of the famous Anglo-Saxon Sutton Hoo helmet; and figurines from the (pre-Viking) Vendel period have been found with immense curving horns on their helmets. So something of the sort did exist in ancient Scandinavian culture, but probably only as dance headdresses and not as battle gear. The Sutton Hoo and Coppergate helmets, and the few others we have, had only small crests at the peak, decorative but also usable as strap-loops to hang the helmet from your pack. (We know Vikings didn't wear them all the time; the king Harald Hardrada made a verse about being caught without his.) However, at that time people assumed everything old-Scandi was Viking, and conflated them into the romantic stereotype. Wagner's designer Doepler, who was famously earnest about "authentic" costume (too much so for Wagner's taste, it seems) can hardly be blamed for picking up the stereotype. However, speaking from memory, I don't think he actually included many horned helmets as such -- maybe even none at all. What Doepler used was the equally spurious winged helmets, and he gave them, presumably symbolically, to divine characters -- Siegfried inherits his from Brunnhilde. Lesser figures don't seem to have them; Hunding, for example, just has a bone twisted in his hair. So it's a bit hard to put all the blame on RW!
But you have to take this interview with a pinch of salt, anyway. For example, the Vikings *did* have navigational instruments; we've found them. One is the remains of a notched disc with upright centre, which registers the direction of shadow like a sundial and can be used to maintain a steady direction. This has been tested in the replica longship Harald Harfagri, and it works, Another was called "sunstone", iceland spar, which polarizes light like a modern filter, and can be used to find the sun even behind clouds. These worked at least as well as the medieval and Arabic instruments like the cross-staff.