[vlovich123]

Could this be adapted into a voxel system? Seems like it could be cheaper than LIDAR which are a huge cost for why the HW for self-driving systems are so expensive & work in far more environments that LIDARs struggle with. I suspect getting multiple directions simultaneously is hard?

[itishappy]

Not without significantly complicating your antenna setup (and the data processing setup too). You guessed it, getting multiple directions simultaneously is hard. Note how the current system only detects distance and speed in 1 dimension.

Here's an analysis from someone smarter than me:

> To enable the new features, radar systems now use multiple input/multiple output (MIMO) antenna arrays for high-resolution mapping. Traditional radar systems usually contain two to three transmitting antennas and three to four receiving antennas, which lead to a beam providing limited short-range coverage and a narrow field of view unable to generate images. The limited angular resolution is insufficient to differentiate among vehicles, pedestrians, or objects that are close. The MIMO approach increases the underlying channels from only nine to anywhere between 128 and 2,000. Given radar’s significantly lower costs — even with all the enhanced technology — it’s easy to see how the two technologies will increasingly be on more equal footing.

https://www.oliverwyman.com/our-expertise/insights/2023/jul/...

[user_7832]

So would this mean that with a few more transmitting and receiving antennas it could have comparable resolution to lidar?

[itishappy]

In theory, though it sounds like to compete with LIDAR it will need about 1000x more antennas, with a related increase in electronics.

[beeeeerp]

Cutting-edge AESA radar like on the F-35 is incredible. It actually looks like a black and white photograph. I think your guess on antennas is roughly correct based on what we know about modern AESA.

[KeplerBoy]

Isn't that Synthetic Aperture Radar though? You can get similar results (black and white aerial pictures) by strapping a pretty basic siso radar system on a drone.

[beeeeerp]

I’m honestly not sure what the difference is. I kind of understand SISO, MIMO, and beam steering concepts, but just the basics from nerding out on my Starlink dish.

This is what I’m talking about: https://www.twz.com/f-35-will-get-new-radar-under-massive-up...

Specifically this image: https://www.twz.com/uploads/2023/01/03/20065813381381024.jpg

I don’t know how targeting works, but with this level of resolution, I think basic image algorithms can start to come into play. It blows my mind.

[user_7832]

Any idea if these antennas can be made small/on a PCB, effectively miniaturizing them?

[itishappy]

Yup.

https://www.youtube.com/watch?v=iOmdQnIlnRo&t=1991s

[user_7832]

Thanks!

[pbmonster]

Look at the forward looking automotive 4D (distance, speed, azimuth angle, elevation angle) radar systems. The new ones work at around 80GHz, and the entire thing comes in one integrated, tiny package, 16x16 phased array antenna already included with the MCs and FPGAs on the same board.

To go from those 4D radar maps to a voxel system requires a whole lot of software, of course.

The end goal seems to be to beat LIDAR on price and reliability (turns out moving mirrors don't like years of constant vibrations), while delivering enough resolution for self-driving.