MMWAVE-L-SDK: IWRL6432: question about the range profile

Hello Chris.

Chris Meng said:

1. How to convert the range profile value output from serial port to dB which showed in above snapshot? 

You can refer to this thread for how to convert the range profile output to relative power, which is the dB value you see.  I've attached the image showing this equation below.

Chris Meng said:

2. I think the x-axis is range (meter), but the wave seems not at the right location. From above snapshot, you will see the target is about 2.43m, but the peak of the wave is close to 2.11, instead of 2.46. Would you pls to check?

I will look into this and will get back to you before Monday regarding why this may be happening.

Sincerely,

Santosh

Santosh,

Thanks for sharing the equation. But I can't get the value shows on the visualizer. I used MotionDetect_1TX-1RX.cfg.

range profile value =0x5535=21,813

NumVirtAnt=1

numRangbins=256/2=128

I used Excel to calculate with formula =(21813)*(2^(LOG(1,2))/512*1)*20*LOG10(2)+20*LOG10(32/128)=244.4575227.

The value seems too big. Would you pls help to check what is missed?

Thanks,

Chris

Hello Chris.

I am getting the same value.  I would double check your range profile value as I do not know where you are getting that value from, and make sure it corresponds to the same point you are looking at on the visualizer.  Where are you getting your range profile value from?

Sincerely,

Santosh

Santosh,

I checked the value as below. 

I tried to find the related formula in GUI source code, but failed to find log related code (Math.log2). Would you pls help to check if I miss anything?

Thanks,

Chris

Hello Chris.  I have relayed this to experts on the visualizer and will get back to you by Wednesday.

Sincerely,

Santosh

Hello Chris.

Sorry for the delay in response.  I talked to some experts and they noted that 1)  this equation is out of date and the current visualizer uses a different equation.  I will ask to get an updated formula.

For your second question, the graph shows an approximation of the range, and there is significant post-processing done on the device before it is outputted, which may lead to the discrepancy that you see.

Sincerely,

Santosh