Technology Selector
Four questions about the site, not about the sensor. The result shows which of the four technologies your conditions ruled out — so you can see the reasoning, not just the answer.
Why the answer is often mmWave radar
mmWave radar wins most combinations for a structural reason, not a commercial one: it is the only one of the four that measures range to a stationary target while also being unaffected by rain, wind and darkness, and working behind a sealed plastic housing.
Everything else gives up at least one of those. PIR cannot see a still person. Ultrasonic cannot survive wind. LiDAR cannot survive rain or a dirty window. So as soon as your site has two or three of those conditions, the field narrows to mmWave radar.
That is why the result page also shows what would change if you loosened one condition. If a cheaper technology becomes viable with a small change to the installation, that is worth knowing before you specify anything.
What this tool does not do
- It does not size the sensor — use the range calculator for that.
- It does not check whether your chosen band is legal where you install — use the band compliance lookup.
- It does not price anything.
Want a second opinion on the result?
Send the site description. I will tell you whether the recommendation holds up and which specific parts to ask a vendor about.