Stellar 105683 2-Stage Radar Motion Sensor

and welcome back now today we're talking about microwave movement detectors what are they well physically they look like something like this which is basically a microwave transmitter and receiver all packaged in one and it works by detecting the received microwave in the same way as perhaps a PIR might but this time it relies on the Doppler effect to get the information about the movement so you can imagine this was if this was built into the front of a speed gun say a police begun that is the microwaves will be transmitted from here received on the other side and the signal can then be processed and from that you can work out what the speed of the vehicle approaching is how does it do that well basically just like it is with them a fire engine it goes past you and you're here to sound it and then drive again and that's not to some kind of illusion that really does happen the sound is