this post was submitted on 17 Sep 2023
426 points (71.9% liked)
Technology
60079 readers
3302 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Yeah, it uses radio frequencies. RaDAR stands for “Radio Detection And Ranging”. It uses radio waves (usually in the microwave bandwidth) to detect things. Basically, since those radio waves are affected by the Doppler effect, you can have a computer do some math to determine the speed of whatever those waves reflected off of. Because the Doppler effect changes a wave based on how fast an object is moving relative to an observer. So if you’re a stationary observer, you can figure out how fast an object is moving relative to yourself, purely based on how much that moving object changes the waves you’re reflecting off of it.
Every wave is affected by Doppler effect.
When a car rushes your way, it’s a tiny bit bluer, a little bit hotter, it’s drivers’ phone is operating on a slightly higher frequency and it sounds higher. According to you.
Well… also according to most physicists.
That's like all relative dude