Detail about radar data

Hello guys,

My question is

  1. In the radar format description, it says v_comp was compensated by ego-motion. What does the ego-motion mean here? Is it the ego-motion caculated by only radar? or ego-motion provided by ground truth GPS/INS.

  2. The technical documentation of Continental ARS40X radar shows that its output mode can be set by “RadarCfg_OutputType” parameter, so what is output mode you set in your dataset, cluster mode or object mode?

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Hi, sorry for the delayed response.

  1. Yes, the ego motion comes from our lidar-based localization algorithm (what’s available as ego_pose in nuScenes).

  2. We’re receiving the raw clusters.

Hello @holger-nutonomy, thank you for the reply. I notice there are both radial and angular velocity information in v (before compensated) but I believe Continental radar can only provide radial velocity of clusters. Did you do any tracking process to caculate angular velocity of clusters?

Sorry, I missed the last question. I don’t think we provide radial velocity: https://github.com/nutonomy/nuscenes-devkit/blob/master/python-sdk/nuscenes/utils/data_classes.py#L292
In any case, what we provide is directly the output of the radar.

Hi,

What are the vx_rms and vy_rms values in the RADAR data? Can you elaborate.?

The definition according to the manual is “Standard deviation of longitudinal relative velocity” and “Standard deviation of lateral relative velocity”. I don’t know what it is the standard deviation of. Perhaps the radar is taking multiple measurements?