Xtalk calibration buffer

[VToma.11]

I need to find out what data does xtalk buffer provide to sensor. I know what some parts of it mean, but I need to know what is the meaning of all parts. Is there any documentation about it?

[Zhiyuan.Han]

Hi WJLO

Your formular is basically right, except the SPAD count, the SPAD cound will be adjusted by return signal, if return signal is high, then the SPAD number will decrease, if target signal is low, SPAD number will increase to collect more signal. 

Br

Zhiyuan.Han

[Zhiyuan.Han]

Hi WJLO,

The shape will be a generic one, not the 64 separate ones.

Br

Zhiyuan.Han

[WJLO]

Hi Zhiyuan.Han,

   If there is only one set of histogram shapes during ranging, how can it distinguish the objects in the front and back and in different areas during distance measurement?

[Zhiyuan.Han]

Hi WJLO

When disable xtalk compensation, the total return signal rate will be merged signal which include xtalk and target return signal. Actually the shape is used to extract xtalk from the merged signal, if you visualize the xtalk shape, you will see the shap data are centered at the beginning of the bin, which means xtalk is come from short distance. 

For the real target, the histogram bin will be centered at different bins depend on target distance, if the target is far at around 3.8 meter, the center will be at the end of the bins. 

Br

Zhiyuan.Han

[WJLO]

Hi Zhiyuan.Han,

  What I mean is 8x8 zone case. In the case of multiple object detection, how to use one shape and 64 Grids to distinguish the distance of different objects?

[Zhiyuan.Han · Accepted solution]

Hi WJLO

For multiple object detection, normally we have two cases, one is multiple target inside FOV, this is detected with multizone feature, and the 2nd one is multi target per zone, as our TOF sensor support maximum 4 targets per zone, I think you are talking the 1st case. 

For each zone ranging, it will use separate zone grid value plus the generic shape value for xtalk correction. so there will be 64 combinations for 64 zones. 

Br

Zhiyuan.Han