Roto tes KM FI ie 10.+1h 45M! 8.t1h IGM 14th 59M | 9.+1h 27M 12.4 2h 14M 800~ 600 400 200-— kM =the ‘ 600 200 2 3 4 6 s 10 4MCc- Fige 306 = Ionospheric Records at Rongerik Following Shot 1 by 59 min ’ to 2 hr 14 min, Showing UnusualSporadic-E and Fl Development Shot 2plus (see Fige 307) 39 min - first faint indicatim of Es (at 110 km just above 4, mc), very weak due tv absorptio 52 min - "spread" Es echoes, somewhat stronger but still weakened by absorption 1 hr 13 min ~ many levels of Es 1 hr 34 min - stronger, multiple level Es, typical of halfhour period centered here 30 SECRET