Sounding Data » Hodograph The Polar Coordinate Chart
For a hodograph, wind vectors are plotted on a polar coordinate chart. The axes of the chart represent the four compass directions. All the wind vectors extend from the origin and point in the direction of the wind's movement. Since the vector length indicates speed, concentric circles drawn around the origin represent constant wind speeds. For example, this hodograph shows that both the 4- and 5-km winds are 25 m/s, although their wind directions are from the west and west-northwest, respectively.