Fig. 18From: Relationship between topography, tropospheric wind, and frequency of mountain waves in the upper mesosphere over the Kanto area of JapanMethod for estimating elevation data. a “Elevation tile” provided by the Geospatial Information Authority of Japan, b elevation data calculated from the “elevation tile,” c mountain ridgeline extracted from b using the method of Iwahashi (1994), d enlarged view of the yellow inset in c and definition of the direction of the mountain ridgeline θʹBack to article page