In simple words, windsocks are basically a device that is used to determine the strength and direction of the wind flow. It is mostly found in open areas such as seaports, highways, airports and mountainous regions. Its shape resembles that of a conical tube and the opening end is tied to a windsock pole. So the closed end i.e. opposite end is indicative of the wind’s direction.
Moreover, it is used to facilitate pilots and airports in getting sufficient knowledge on wind conditions, specifically its direction and power.
Determining the winds speed/strength with this instrument is not as difficult as one would imagine it to be. First and foremost, you need to draw an image of a sock at a time when its extension is maximal (full). For a precise measurement, ensure that there are no bends in the picture. Now this will be your baseline of 17 miles per hour. To be on the safe side, just check with your weather station to ensure that the wind is not below the baseline set.
Thereafter, draw another sketch on a day when there’s little-to-no wind blowing. Once you have done that, wait for a day in which the weather station reports the wind to be blowing continuously and at a particular speed (4 miles per hour, for example). When this happens, you draw another sketch of it.
You may have to do this several times in order to get different shapes (sizes) of it, at different speeds. Then finally you will create a chart from the data you have gathered. The chart must have a number of sketches showing different shapes of the windsock reported at different speeds.