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"Its particular superpower is that it can generate high resolution images of its surroundings much better than radar can." Is this true tough? Car radars are f

"Its particular superpower is that it can generate high resolution images of its surroundings much better than radar can." Is this true tough? Car radars are fixed. I guess a comparable lidar would be fixed too and have n points for n lasers. A rovolving radar would have continuous resolution around while a lidar samples? I thought the advantage of lidars were accuracy and being better at measuring heights of objects, where as radars flatten the view.

lupusreal 2y ago
Very high tech radars can generate amazing imagery, but they'll never top what lidar can do. Conceptually they're both doing the same sort of thing using EM radiation, but lidar uses a much smaller wavelength which gives it an intrinsic resolution advantage. Particularly at distances and with hardware sized relevant to cars.
ender7 2y ago
The issue isn't one of fixed vs rotation, it's that radar can't fundamentally achieve the resolution necessary to distinguish important features in the environment. It's easily fooled by oddly-shaped objects, especially concave features like corners, and so while it's great for answer the question of "am I close to something" it's not reliable for telling you what that something is, especially at longer ranges.
xnx 2y ago
I believe automotive radar has a cone of sensitivity that is read as a single "pixel" worth of data. Even if the radar spun like lidar, the radar cone of sensitivity is thousands of times wider than the lidar beam so you can't make much of a picture with radar.
- 0_____0 2y ago
  IIRC the data coming out of the Conti radars was preprocessed to give bearing, distance, and size of an object in the FOV of the unit. I don't know if I ever saw the true raw data out of one of them, but I'm curious what it looks like.
  - itishappy 2y ago
    I'd be curious if the design of the Cybertruck affects readings at all. It's got angles straight outta an F-117.
    - 0_____0 2y ago
      I reckon it's probably not that bad, there are big surfaces that are almost normal to what would be incoming radio energy. Stealth shapes tend to reflect energy in a completely different direction from the source.
      - itishappy 2y ago
        Here's the closest thing to data I've been able to find. I have no idea what to do with this info. https://x.com/jwt0625/status/1848218860513628203 https://x.com/jwt0625/status/1848218860513628203
        0_____0 2y ago
        The polar plot at the end would be useful if there were plots for other cars and trucks to compare to. I'm assuming that it's a simulation?
    - rightbyte 2y ago
      I think "stealth" planes assumes the radar is under the plane on the ground? For the geometry. And they have some color or alloy that reflect less.
      - 0_____0 2y ago
        It's cooler than that these days - under the paint are antennas plated? printed? onto the skin panels that are tuned to absorb specific frequencies of interest.
  - rightbyte 2y ago
    Ye I have a hard time imaganing how a car radar image looks like. On boat radars it seems like the radar have really high resolution (can see much further than lidars) but have worse accuracy. I.e. things looks like blobs. A lidar image at 50+ meters is very sparse.

lupusreal 2y ago

Very high tech radars can generate amazing imagery, but they'll never top what lidar can do. Conceptually they're both doing the same sort of thing using EM radiation, but lidar uses a much smaller wavelength which gives it an intrinsic resolution advantage. Particularly at distances and with hardware sized relevant to cars.

ender7 2y ago

The issue isn't one of fixed vs rotation, it's that radar can't fundamentally achieve the resolution necessary to distinguish important features in the environment. It's easily fooled by oddly-shaped objects, especially concave features like corners, and so while it's great for answer the question of "am I close to something" it's not reliable for telling you what that something is, especially at longer ranges.

xnx 2y ago

I believe automotive radar has a cone of sensitivity that is read as a single "pixel" worth of data. Even if the radar spun like lidar, the radar cone of sensitivity is thousands of times wider than the lidar beam so you can't make much of a picture with radar.

0_____0 2y ago
IIRC the data coming out of the Conti radars was preprocessed to give bearing, distance, and size of an object in the FOV of the unit. I don't know if I ever saw the true raw data out of one of them, but I'm curious what it looks like.
- itishappy 2y ago
  I'd be curious if the design of the Cybertruck affects readings at all. It's got angles straight outta an F-117.
  - 0_____0 2y ago
    I reckon it's probably not that bad, there are big surfaces that are almost normal to what would be incoming radio energy. Stealth shapes tend to reflect energy in a completely different direction from the source.
    - itishappy 2y ago
      Here's the closest thing to data I've been able to find. I have no idea what to do with this info. https://x.com/jwt0625/status/1848218860513628203 https://x.com/jwt0625/status/1848218860513628203
      - 0_____0 2y ago
        The polar plot at the end would be useful if there were plots for other cars and trucks to compare to. I'm assuming that it's a simulation?
  - rightbyte 2y ago
    I think "stealth" planes assumes the radar is under the plane on the ground? For the geometry. And they have some color or alloy that reflect less.
    - 0_____0 2y ago
      It's cooler than that these days - under the paint are antennas plated? printed? onto the skin panels that are tuned to absorb specific frequencies of interest.
- rightbyte 2y ago
  Ye I have a hard time imaganing how a car radar image looks like. On boat radars it seems like the radar have really high resolution (can see much further than lidars) but have worse accuracy. I.e. things looks like blobs. A lidar image at 50+ meters is very sparse.