Questions tagged [radar]

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Radar Antenna Quantity and functional performance

Millimeter wave radar SoC (system on a chip) are evolving from 4 to 72 antennas on a single chip. Is there a simple (ELI5) explanation as to why 72 antennas (vs 4) are desirable? My intuition ...
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285 views

Doppler Cone: What exactly is it?

I'm trying to understand Synthetic Aperture Radar (SAR). It appears that it makes use of what's called a "Doppler cone". I understand Doppler frequency shifts of light, but I'm not sure what the cone ...
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32 views

Conjugated-Phase Matching

I am working on imaging applications of phase-conjugation in optics, in particular phase-conjugation imaging from recorded holograms. I have found several useful sources, but I cannot find a book ...
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1answer
30 views

Loss of beam power over astronomical distances

pardon my choice of words, but English isn't my native language, so I might use the wrong terms at some places. Beside this, I do have a hypothetical situation which might be a bit off reality (...
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90 views

Doppler radar electric field expressions

Consider the right handed coordinate system $(x,y,z)$ in which a stationnary radar is positioned at the origin and a metallic plate (initial position $z_0$) that is moving along the $z$ axis with ...
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33 views

Speed between two cars with radar

I found a programming problem that calculated the speed between two cars as below and I would like to know how the calculation is done. It is about determining the speed of lead car. The coordinate ...
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5 views

Signal's phase change requirement for benefiting from coherent integration

Maximizing the potential of coherent integration requires that the signal’s phase vary by less than 90deg over the entire integration interval. What exactly does that mean in a FMCW radar application ...
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1answer
178 views

Radar waves all waves not working under water

was just wondering why all waves don't work under water for? I know they work for 10 meters "but" after that they don't. Does it have anything to do with it's wavelength? Or is it just that the ...
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1answer
28 views

reading radar / waves changing after hitting each other

Can you read a radar or any wave when it hits another wave...it changes? So say a radar wave hits another wave changing it miles away, can you get info of that hit happening miles away from the radar ...
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1answer
17 views

Is there a way to recalculate radar detection range given the old and new probability of detection and false alarm?

I'm reading through some radar books and I'm trying to find out if there's an easy method or equation to recalculate radar detection range given only the original radar detection range, original ...
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233 views

Looking for full equation for radar cross section of corner reflector

There's a well-known formula for the RCS of a corner reflector (aka corner cube), to wit $ \sigma \varpropto \frac{L^4}{\lambda^2} $ . I've found several sources which cheerfully say "...valid for $ ...
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759 views

Radar Vs. Sonar

What is the true difference between radar and sonar? My understanding is that radar uses a reflected EM wave, while sonar uses a compression (shock wave) of the material it's in. (It compresses water, ...
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Can a radar detect non-solid bodies?

Would a radar detect a body of hot gas or plasma? A normal cloud? Would it detect dark matter? Could you tell the difference or would you believe radar sees a solid body? P.S. This is not a ...