History of Doppler Weather Radar

The Doppler weather radar is a special kind of radar, that is used to locate precipitation and predict its future movements and intensity. The data so obtained, is analyzed carefully, to ascertain the nature of storms and their potential to cause a calamity. It was developed by the National Severe Storms Laboratory (NSSL) in the United States.

It uses the principle of the Doppler Effect for the purpose of studying the frequency of waves in the air, to ascertain the movement and direction of wind, and to forecast the weather.

According to its theory, when the source of the waves approaches the observer (or radar), the frequency of the waves increases, and during recession, the frequency of the waves decreases. Thus, by studying the frequencies, the target location as well as the radial velocity of thunderstorms can be identified.

The history of weather radars dates back to the time of World War II. During this period, scientists who were working as operators of military radars, detected some sounds of returned echoes at the time of rainfall or snowfall.

After the war, these scientists continued their research work in their respective countries, to formulate a method to utilize the echo patterns.

David Atlas from the United States, was one of the first of these researchers who made a working weather radar. In Canada, J.S. Marshall, R.H. Douglas and their team made a major breakthrough by establishing a relation between the radiant energy of the radar and the rate of falling of rainwater on the ground.

Scientists from the United Kingdom closely studied the characteristics of different types of clouds.In the 50s and 60s, several weather services across the globe, developed reflectivity radars, that helped in measuring the location and magnitude of precipitation.

In 1964, NSSL came into being, and started experimenting on the possible uses of the Doppler Effect on its radar. In the 70s, weather radars became more standardized, with organized networks. Simultaneously, devices that could capture radar images were also created.

There was an increase in the number of scanned angles, to obtain a distinct three-dimensional image of the precipitation. During this time, thunderstorms could be examined only at Alberta Hail Project in Canada and NSSL in US.

In May 1973, Union City, Oklahoma, saw massive devastation due to a tornado. The total life cycle of this mayhem was recorded by a Dopplerised radar developed by NSSL.

Studies of its life cycle revealed specific movements of clouds, before the tornado reached the ground. This revelation persuaded the National Weather Service, to accept this device as an important tool for weather forecasting.

The period between 1980 to 2000, saw the developed countries depending on radar networks. In this period, US, Canada, and France switched over from conventional radars to Doppler weather radars; their biggest advantage is that not only can it track the position and intensity if the particles in the air, but can also track their relative velocity.

The early 2000s saw many advances in the field of computer technology, which led to even more accurate reading, and forecasting of the weather.

Further research for better evaluation of the data provided by radars is underway. They can make the predictions even more precise, by targeting locations of thunderstorms as well as their radial velocity. As a result, it will be possible to save many lives from the mayhem following a thunderstorm.