I slightly understand the hook and the old Doppler showing a purple or dark color representing debris, but I’m sure that’s only if the debris field is that high up and a large amount. When looking at radar now with representations of tornadoes, I find it hard to pick out which part of the radar shows it. I’m sure this won’t be a popular question but anyone with knowledge of radar, your expertise would be appreciated.
In: Technology
What a radar signal is reflected by depending on the frequency/wavelength. If you have a weather radar the wavelength of 1-10 cm and then water droplets and ice in the air will reflect back the signal to you. What you see in a cloud is just that water droplets or ice.
10 cm is 3 GHz and a microwave oven is a 2.4 GHz signal. So if you can get water to absorb microwaves you can get it to reflect slightly different frequencies too.
For radar designed to detect aircraft, you use different frequencies that pass through the clauses
So a weather radar show is not debris but the water liquid or solid in the clouds.
A Doppler radar uses pulses in a way so you can determine the speed and direction of the thing, it reflects from. The principle is the same way a pitch of an ambulance of a police siren is different depending on if it moves toward or away from you.
So what you can see o a weather doppler radar you can see the clouds and the direction. So you can spot a tornado by looking for a circular high-speed pattern.
Doppler radar can measure wind speed, so seeing the two sides of a funnel clouds winds can give a strong identification, since one side will be moving towards the radar at high velocity while the other is receding from it at similar speeds. This makes a strong case for rotation and approximate strength of the tornado, as well as a good estimate as to its direction.
The “doppler” means the radar can tell whether the reflection is from something moving towards or away from the radar site, and how fast. If you have fast wind moving towards the radar site right next to fast wind moving away from the radar site, that’s probably a tornado.
For example, if you go to this radar site: https://www.wunderground.com/radar/us/ok/oklahoma-city/tlx
where it says “base reflectivity” you can switch it over to “base radial velocity”.
You will usually see a hook echo. On a Doppler radar, it’s a red area that looks coma shaped. Otherwise, there can be a debris field or the wind shear will show up moving in opposite directions as large red areas.
[Hook](https://www.accuweather.com/en/weather-news/how-to-recognize-a-radar-confirmed-tornado/328885)
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