How do you measure wind speed?

There are a variety of wind measurements that you can make. Lower level winds 0 - 300 feet from the ground are most commonly measured with an anemometer, although a laser can also be used. The Laser really doesn't measure the wind, rather it measures the speed of the particulate matter suspended in the air. Upper level winds are most commonly measured with weather balloons. The balloons can be tracked with precision tracking radars or more commonly carry their own data package called a sonde. The sonde package will measure parameters such as position (via GPS), temperature, and humidity. With these time tagged parameters wind speed and other variables can be calculated and tabulated for various altitudes. This data is crucial for aircraft pilots. They monitor the weather especially winds very closely on a daily basis.

A barometer measures air pressure not wind speed. Air speed is measured in an aircraft by means of a pitot tube feeding air into a vacuum driven airspeed indicator. There are several measurements for airspeed, i.e. true airspeed, relative airspeed, calibrated airspeed, etc. It is important for a pilot to know the outside airspeed and direction of the wind so that he can calculate his speed over the group and measure the amount of degrees on the compass he is being driven from the course over the ground he wishes to follow so he can adjust the course he steers to arrive at the precise point at the conclusion of his flight. Meteorologists measure air speed with an anometer. This information is used in predicting how fast weather systems are moving over the ground and in which direction they are moving.

Wind speed can be measured by a variety of tools. The most common method is by using an anemometer, consisting of a rotating vane.

By an intrument called an anemometer. The sensor part can be rotating vanes or thermistors arranged in the wheatstone bridge configuration with one thermistor used as aspeed detector. This is considerably more sensitive than the mechanical types.

Of course there are other types like venturi flow meters to measure various types of fluid speeds.

You can visit www.wikipedia.org for more info.

Speed =Distance/Time

Simple Method

Wind mill's rotating cock,Count the circles in a min. and calculate.

Take 5-6 observations and calculate average,speed.

u can measure the no of ripples in water per second or u can use Anemometers

using an anemometer

with two cups attached to a motor.

google for anemometer.

Do you mean what instrument or are you asking about knots/MPH?