How to related the x,y from the radar to the bounding boxes

Hello
As I understand, for developing a tracker for a moving object, we need to compare each and every coordinate of the moving object in the radar data with the bounding boxes, which are available in the metadata of the sample annotations. But the data given is
‘translation’: [409.989, 1164.099, 1.623],
‘size’: [2.877, 10.201, 3.595], for a single annotated object
Does this mean that the base coordinate of the box is 409.989, 1164.099, 1.623 and the size of the box is 2.877, 10.201, 3.595 in the x, y, z directions?

Also can you give me a suggestion as to how to keep track of the objects which are present in one sample data with the other following sample data?

Hi.

Does this mean that the base coordinate of the box is 409.989, 1164.099, 1.623 and the size of the box is 2.877, 10.201, 3.595 in the x, y, z directions?

Yes. The translation is in global coordinates.

Also can you give me a suggestion as to how to keep track of the objects which are present in one sample data with the other following sample data?

As you can see in the diagram at https://github.com/nutonomy/nuscenes-devkit/blob/master/docs/schema_nuscenes.md, each sample_annotation is linked to an instance, which gives it a unique ID across time. The easiest way to get the annotation in the next keyframe is to use sample_annotation[‘next’].