National Geographic : 1950 Oct
557 I'. S. Air Force, Official After a "Hairy Hop," Tired Storm-seekers Relax over Cups of Coffee This crew of a recon plane hasn't yet shed life jackets at Kindley Air Force Base, Bermuda. One man points to the spot where they chased a hurricane. Prominent are call letters of radio stations that keep contact with transatlantic airliners. Two diagonal black stripes mark flight tracks between Bermuda (lower left) and England. Cross marks (upper left) are beam paths of radio range stations on the mainland. Both Navy and Air Force now use new radar to spy out and pinpoint hurricane centers while the spotting plane stays well out side the roughest weather. This equipment is especially useful for tracking hurricanes at night, when less sensitive sets would be largely inadequate and when flying near the storm center would be dangerous to aircraft. Night flights of radar-equipped Navy B-17's from Patuxent River Naval Air Station, Mary land, and of Air Force radar planes from Ber muda, all requested from Miami, supplement the daytime hurricane hops. What is the image the radar scanner sees, or photographs, on his scope? To the un initiated the "picture" looks like rather shape less patches, luminous and greenish in appear ance. But the radarman says: "See these glowing crescents? They show where rain is heaviest; their curving shape reveals the hur ricane eye" (page 550). You learn that radar pulses bounce back from water droplets in the air. Echo pulses shape up on the radar screen into patterns that trained observers can instantly identify. "The center of a tropical cyclone shows up so well on radar," Captain Ellsaesser ex plained, "because the big and copious rain drops in the clouds around the eye toss back the strongest echoes." Radar Watches Storm Move In Line-of-sight range is necessary for radar reach, just as it is for television reception. So a high-level flight aiming by radar at a high-level target (the hurricane two miles above sea or land) obviously allows the longest straight-line sight (actually hundreds of miles) without interference from the earth's curvature. The most precise "fix" on a storm is possible when radar shows the hurricane eye and identifiable islands or other landmarks in the same view.