Radar point z value


From the mini dataset, the z value of radar point is non-zero.
Does it mean the radar have antenna elements in elevation?
Or it means something else?


Hi @fjin4. I think there is a misunderstanding here. If you just open the pointcloud directly with

from nuscenes.nuscenes import NuScenes
import os
from nuscenes.utils.data_classes import RadarPointCloud
nusc = NuScenes()
rpc = RadarPointCloud.from_file(os.path.join(nusc.dataroot, nusc.sample_data[0][‘filename’]))
assert (rpc.points[2, :] == 0).all()

then you will see that all z values are 0 (relative to the sensor height). However, if you open them with a function like https://github.com/nutonomy/nuscenes-devkit/blob/master/python-sdk/nuscenes/nuscenes.py#L533 , then it will transform them to pointcloud to a different coordinate system.

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Hi there, as far as I can see this link is no longer pointing to a specific function. Would it be possible to clarify which one are you referring to?


There are a number of methods that don’t do what you want, e.g. https://github.com/nutonomy/nuscenes-devkit/blob/9b492f76df22943daf1dc991358d3d606314af27/python-sdk/nuscenes/nuscenes.py#L863.